Feat(opsgenie): deprecate Opsgenie plugin (#54190)

Hide the Opsgenie plugin if it's not installed. If it is, mark it as
legacy.

Fixes ER-1790

Author: mifu67

Diff for: src/sentry/integrations/opsgenie/integration.py

@@ -159,7 +159,7 @@ def schedule_migrate_opsgenie_plugin(self):
 
 class OpsgenieIntegrationProvider(IntegrationProvider):
     key = "opsgenie"
-    name = "Opsgenie (Integration)"
+    name = "Opsgenie"
     metadata = metadata
     integration_cls = OpsgenieIntegration
     features = frozenset([IntegrationFeatures.INCIDENT_MANAGEMENT, IntegrationFeatures.ALERT_RULE])

Diff for: src/sentry/plugins/__init__.py

@@ -5,4 +5,5 @@
     "slack",
     "jira",
     "pagerduty",
+    "opsgenie",
 )

Diff for: src/sentry/rules/actions/notify_event_service.py

@@ -25,7 +25,7 @@
 from sentry.utils.safe import safe_execute
 
 logger = logging.getLogger("sentry.integrations.sentry_app")
-PLUGINS_WITH_FIRST_PARTY_EQUIVALENTS = ["PagerDuty", "Slack"]
+PLUGINS_WITH_FIRST_PARTY_EQUIVALENTS = ["PagerDuty", "Slack", "Opsgenie"]
 
 
 def build_incident_attachment(