Enhance widgets unit tests and increase coverage

Author: ChristianZaccaria

src/codeflare_sdk/common/widgets/widgets.py

@@ -137,6 +137,7 @@ def _on_delete_button_click(self, b):
 
         # Refresh the dataframe
         new_df = _fetch_cluster_data(namespace)
+        self.ray_clusters_df = new_df
         if new_df.empty:
             self.classification_widget.close()
             self.delete_button.close()
@@ -385,15 +386,19 @@ def _fetch_cluster_data(namespace):
     namespaces = [item.namespace for item in rayclusters]
     num_workers = [item.num_workers for item in rayclusters]
     head_extended_resources = [
-        f"{list(item.head_extended_resources.keys())[0]}: {list(item.head_extended_resources.values())[0]}"
-        if item.head_extended_resources
-        else "0"
+        (
+            f"{list(item.head_extended_resources.keys())[0]}: {list(item.head_extended_resources.values())[0]}"
+            if item.head_extended_resources
+            else "0"
+        )
         for item in rayclusters
     ]
     worker_extended_resources = [
-        f"{list(item.worker_extended_resources.keys())[0]}: {list(item.worker_extended_resources.values())[0]}"
-        if item.worker_extended_resources
-        else "0"
+        (
+            f"{list(item.worker_extended_resources.keys())[0]}: {list(item.worker_extended_resources.values())[0]}"
+            if item.worker_extended_resources
+            else "0"
+        )
         for item in rayclusters
     ]
     head_cpu_requests = [