chore: Register flag that consolidates all span-first UI (#68911)

Create an options backed flag for all starfish UI so we can enable them

Author: shruthilayaj

src/sentry/conf/server.py

@@ -1902,6 +1902,8 @@ def custom_parameter_sort(parameter: dict) -> tuple[str, int]:
     "organizations:sso-saml2": True,
     # Enable standalone span ingestion
     "organizations:standalone-span-ingestion": False,
+    # A single flag for all the new performance UI that relies on span ingestion
+    "organizations:spans-first-ui": False,
     # Enable the aggregate span waterfall view
     "organizations:starfish-aggregate-span-waterfall": False,
     # Enables the resource module ui

src/sentry/features/temporary.py

@@ -232,6 +232,7 @@ def register_temporary_features(manager: FeatureManager):
     manager.add("organizations:sourcemaps-bundle-flat-file-indexing", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
     manager.add("organizations:sourcemaps-upload-release-as-artifact-bundle", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
     manager.add("organizations:stacktrace-processing-caching", OrganizationFeature, FeatureHandlerStrategy.INTERNAL)
+    manager.add("organizations:spans-first-ui", OrganizationFeature, FeatureHandlerStrategy.INTERNAL)
     manager.add("organizations:standalone-span-ingestion", OrganizationFeature, FeatureHandlerStrategy.INTERNAL)
     manager.add("organizations:starfish-aggregate-span-waterfall", OrganizationFeature, FeatureHandlerStrategy.REMOTE)
     manager.add("organizations:starfish-browser-resource-module-bundle-analysis", OrganizationFeature, FeatureHandlerStrategy.REMOTE)