refactor(pypi): use a macro to define whl_library targets (bazel-contrib#2347)

Summary:
- refactor: Start implementing whl_library_targets
- refactor: start using whl_library_targets macro
- refactor: generate config settings in the new macro
- refactor: copy_files in the new macro
- refactor: move entry_point generation to the macro
- refactor: move the py_library and whl generation to the new macro

This makes the code more maintainable by reducing the amount of tests
that are comparing BUILD.bazel outputs.

Author: aignas

examples/bzlmod/MODULE.bazel.lock

@@ -110,8 +110,7 @@ bzl_library(
     name = "generate_whl_library_build_bazel_bzl",
     srcs = ["generate_whl_library_build_bazel.bzl"],
     deps = [
-        ":labels_bzl",
-        "//python/private:normalize_name_bzl",
+        "//python/private:text_util_bzl",
     ],
 )