revert: remove Microsoft Fabric connector support (#27198) (#28685)

Reverts the implementation added in #27198 (1905f6e), removing the
Microsoft Fabric database & pipeline connector support while keeping the
connection schema definitions intact.

Removed:
- Python clients, sources (database + pipeline), examples, and unit tests
- microsoftfabric/microsoftfabricpipeline setup.py plugin extras
- UI schema loaders and service icon wiring

Kept (schema stays as-is):
- openmetadata-spec microsoftFabricConnection / microsoftFabricPipelineConnection
  schemas and their generated types
- Re-added the service types to unSupportedServices so they are hidden in the UI

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ulixius9

ingestion/setup.py

@@ -214,8 +214,6 @@
     "atlas": {},
     "azuresql": {VERSIONS["pyodbc"]},
     "azure-sso": {VERSIONS["msal"]},
-    "microsoftfabric": {VERSIONS["pyodbc"], VERSIONS["msal"]},
-    "microsoftfabricpipeline": {VERSIONS["msal"]},
     "backup": {VERSIONS["boto3"], VERSIONS["azure-identity"], "azure-storage-blob"},
     "googledrive": {
         "google-api-python-client>=2.0.0",