feat: add BitbucketCloudEntityProvider (new plugin)

Add a new entity provider `BitbucketCloudEntityProvider`
as a new plugin `@backstage/plugin-catalog-backend-module-bitbucket-cloud`.

The new plugin utilizes `@backstage/plugin-bitbucket-cloud-common`
and it fully independent of `@backstage/plugin-catalog-backend-module-bitbucket`
which provides a catalog processors supporting Bitbucket Cloud and Bitbucket Server.

Relates-to: #9923
Relates-to: #10183
Signed-off-by: Patrick Jungermann <Patrick.Jungermann@gmail.com>

microsite/sidebars.json

@@ -149,6 +149,14 @@
           "integrations/bitbucket/discovery"
         ]
       },
+      {
+        "type": "subcategory",
+        "label": "Bitbucket Cloud",
+        "ids": [
+          "integrations/bitbucketCloud/locations",
+          "integrations/bitbucketCloud/discovery"
+        ]
+      },
       {
         "type": "subcategory",
         "label": "Datadog",