feat(database): Register feature flag for database query source UI (#60647)

The data is already available in some SDKs. Going to hide the UI behind
a feature flag while I work on it.

src/sentry/conf/server.py

@@ -1728,6 +1728,8 @@ SENTRY_FEATURES: dict[str, bool | None] = {
     "organizations:performance-database-view": False,
     # Enable database view percentile graphs
     "organizations:performance-database-view-percentiles": False,
+    # Enable database view query source UI
+    "organizations:performance-database-view-query-source": False,
     # Enable removing the fallback for metrics compatibility
     "organizations:performance-remove-metrics-compatibility-fallback": False,
     # Enable performance score calculation for transactions in relay

src/sentry/features/__init__.py

@@ -167,6 +167,7 @@ default_manager.add("organizations:performance-slow-db-issue", OrganizationFeatu
 default_manager.add("organizations:performance-tracing-without-performance", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:performance-database-view", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:performance-database-view-percentiles", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
+default_manager.add("organizations:performance-database-view-query-source", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:performance-screens-view", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:performance-remove-metrics-compatibility-fallback", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
 default_manager.add("organizations:performance-statistical-detectors-ema", OrganizationFeature, FeatureHandlerStrategy.INTERNAL)