fix(core): Typing in docker_client (#702)

Supports:
#305
Related :
#691
#692 #700

Based on #504, kudos @alexanderankin 

```
poetry run mypy --config-file pyproject.toml core/testcontainers/core/docker_client.py 
Success: no issues found in 1 source file
```

Old
```
                    Error Summary                     
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━┓
┃ File Path                                 ┃ Errors ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━┩
│ core/testcontainers/core/version.py       │ 12     │
│ core/testcontainers/core/docker_client.py │ 14     │
│ core/testcontainers/core/image.py         │ 17     │
│ core/testcontainers/core/waiting_utils.py │ 8      │
│ core/testcontainers/core/container.py     │ 20     │
│ core/tests/test_new_docker_api.py         │ 4      │
│ core/tests/test_docker_in_docker.py       │ 2      │
│ core/testcontainers/compose/compose.py    │ 22     │
│ core/testcontainers/compose/__init__.py   │ 2      │
│ core/tests/test_version.py                │ 2      │
│ core/tests/test_ryuk.py                   │ 2      │
│ core/tests/test_registry.py               │ 1      │
│ core/tests/test_image.py                  │ 3      │
│ core/tests/test_compose.py                │ 7      │
└───────────────────────────────────────────┴────────┘
Found 116 errors in 14 files.
```
New
```
                    Error Summary                     
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━┓
┃ File Path                                 ┃ Errors ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━┩
│ core/testcontainers/core/version.py       │ 12     │
│ core/testcontainers/core/network.py       │ 3      │
│ core/testcontainers/core/image.py         │ 17     │
│ core/testcontainers/core/waiting_utils.py │ 8      │
│ core/testcontainers/core/container.py     │ 19     │
│ core/tests/test_new_docker_api.py         │ 4      │
│ core/tests/test_docker_in_docker.py       │ 2      │
│ core/testcontainers/compose/compose.py    │ 22     │
│ core/testcontainers/compose/__init__.py   │ 2      │
│ core/tests/test_version.py                │ 2      │
│ core/tests/test_ryuk.py                   │ 2      │
│ core/tests/test_registry.py               │ 1      │
│ core/tests/test_image.py                  │ 3      │
│ core/tests/test_compose.py                │ 7      │
└───────────────────────────────────────────┴────────┘
Found 104 errors in 14 files.
```

Author: Tranquility2

core/testcontainers/core/config.py

@@ -21,7 +21,7 @@ def use_mapped_port(self) -> bool:
 
         This is true for everything but bridge mode.
         """
-        if self == self.bridge_ip:
+        if self == self.bridge_ip:  # type: ignore[comparison-overlap]
             return False
         return True
 
@@ -63,7 +63,7 @@ def get_user_overwritten_connection_mode() -> Optional[ConnectionMode]:
     """
     Return the user overwritten connection mode.
     """
-    connection_mode: str | None = environ.get("TESTCONTAINERS_CONNECTION_MODE")
+    connection_mode: Union[str, None] = environ.get("TESTCONTAINERS_CONNECTION_MODE")
     if connection_mode:
         try:
             return ConnectionMode(connection_mode)

core/testcontainers/core/docker_client.py

@@ -19,7 +19,7 @@
 import urllib
 import urllib.parse
 from collections.abc import Iterable
-from typing import Callable, Optional, TypeVar, Union
+from typing import Any, Callable, Optional, TypeVar, Union, cast
 
 import docker
 from docker.models.containers import Container, ContainerCollection
@@ -59,7 +59,7 @@ class DockerClient:
     Thin wrapper around :class:`docker.DockerClient` for a more functional interface.
     """
 
-    def __init__(self, **kwargs) -> None:
+    def __init__(self, **kwargs: Any) -> None:
         docker_host = get_docker_host()
 
         if docker_host:
@@ -82,14 +82,14 @@ def run(
         self,
         image: str,
         command: Optional[Union[str, list[str]]] = None,
-        environment: Optional[dict] = None,
-        ports: Optional[dict] = None,
+        environment: Optional[dict[str, str]] = None,
+        ports: Optional[dict[int, Optional[int]]] = None,
         labels: Optional[dict[str, str]] = None,
         detach: bool = False,
         stdout: bool = True,
         stderr: bool = False,
         remove: bool = False,
-        **kwargs,
+        **kwargs: Any,
     ) -> Container:
         # If the user has specified a network, we'll assume the user knows best
         if "network" not in kwargs and not get_docker_host():
@@ -112,7 +112,7 @@ def run(
         return container
 
     @_wrapped_image_collection
-    def build(self, path: str, tag: str, rm: bool = True, **kwargs) -> tuple[Image, Iterable[dict]]:
+    def build(self, path: str, tag: str, rm: bool = True, **kwargs: Any) -> tuple[Image, Iterable[dict[str, Any]]]:
         """
         Build a Docker image from a directory containing the Dockerfile.
 
@@ -151,43 +151,43 @@ def find_host_network(self) -> Optional[str]:
                         except ipaddress.AddressValueError:
                             continue
                         if docker_host in subnet:
-                            return network.name
+                            return cast(str, network.name)
         except (ipaddress.AddressValueError, OSError):
             pass
         return None
 
-    def port(self, container_id: str, port: int) -> int:
+    def port(self, container_id: str, port: int) -> str:
         """
         Lookup the public-facing port that is NAT-ed to :code:`port`.
         """
         port_mappings = self.client.api.port(container_id, port)
         if not port_mappings:
             raise ConnectionError(f"Port mapping for container {container_id} and port {port} is " "not available")
-        return port_mappings[0]["HostPort"]
+        return cast(str, port_mappings[0]["HostPort"])
 
-    def get_container(self, container_id: str) -> Container:
+    def get_container(self, container_id: str) -> dict[str, Any]:
         """
         Get the container with a given identifier.
         """
         containers = self.client.api.containers(filters={"id": container_id})
         if not containers:
             raise RuntimeError(f"Could not get container with id {container_id}")
-        return containers[0]
+        return cast(dict[str, Any], containers[0])
 
     def bridge_ip(self, container_id: str) -> str:
         """
         Get the bridge ip address for a container.
         """
         container = self.get_container(container_id)
         network_name = self.network_name(container_id)
-        return container["NetworkSettings"]["Networks"][network_name]["IPAddress"]
+        return str(container["NetworkSettings"]["Networks"][network_name]["IPAddress"])
 
     def network_name(self, container_id: str) -> str:
         """
         Get the name of the network this container runs on
         """
         container = self.get_container(container_id)
-        name = container["HostConfig"]["NetworkMode"]
+        name = str(container["HostConfig"]["NetworkMode"])
         if name == "default":
             return "bridge"
         return name
@@ -198,7 +198,7 @@ def gateway_ip(self, container_id: str) -> str:
         """
         container = self.get_container(container_id)
         network_name = self.network_name(container_id)
-        return container["NetworkSettings"]["Networks"][network_name]["Gateway"]
+        return str(container["NetworkSettings"]["Networks"][network_name]["Gateway"])
 
     def get_connection_mode(self) -> ConnectionMode:
         """
@@ -235,9 +235,10 @@ def host(self) -> str:
             return "localhost"
         if "http" in url.scheme or "tcp" in url.scheme and url.hostname:
             # see https://github.com/testcontainers/testcontainers-python/issues/415
-            if url.hostname == "localnpipe" and utils.is_windows():
+            hostname = url.hostname
+            if not hostname or (hostname == "localnpipe" and utils.is_windows()):
                 return "localhost"
-            return url.hostname
+            return cast(str, url.hostname)
         if utils.inside_container() and ("unix" in url.scheme or "npipe" in url.scheme):
             ip_address = utils.default_gateway_ip()
             if ip_address:
@@ -251,9 +252,9 @@ def login(self, auth_config: DockerAuthInfo) -> None:
         login_info = self.client.login(**auth_config._asdict())
         LOGGER.debug(f"logged in using {login_info}")
 
-    def client_networks_create(self, name: str, param: dict):
+    def client_networks_create(self, name: str, param: dict[str, Any]) -> dict[str, Any]:
         labels = create_labels("", param.get("labels"))
-        return self.client.networks.create(name, **{**param, "labels": labels})
+        return cast(dict[str, Any], self.client.networks.create(name, **{**param, "labels": labels}))
 
 
 def get_docker_host() -> Optional[str]: