Add health check endpoint and refactor integration response handling

- Introduced a new public health check endpoint at `api/ping/` to verify API responsiveness.
- Refactored integration response handling to utilize a unified success and error response format across various methods in `IntegrationSettingsViewSet`, improving consistency and clarity in API responses.
- Updated URL patterns to include the new ping endpoint and adjusted imports accordingly.

backend/igny8_core/api/schema_extensions.py

@@ -29,7 +29,9 @@ def postprocess_schema_filter_tags(result, generator, request, public):
                     
                     # If no explicit tags found, infer from path
                     if not filtered_tags:
-                        if '/auth/' in path or '/api/v1/auth/' in path:
+                        if '/ping' in path or '/system/ping/' in path:
+                            filtered_tags = ['System']  # Health check endpoint
+                        elif '/auth/' in path or '/api/v1/auth/' in path:
                             filtered_tags = ['Authentication']
                         elif '/planner/' in path or '/api/v1/planner/' in path:
                             filtered_tags = ['Planner']