unified-storage: setup ring to shard requests (#103783)

* Updates the instrumentation_server service to use mux instead of the builtin router, and have it store the router in the module server: this is so we can register the /ring endpoint to check the status of the ring
* Create a new Ring service that depends on the instrumentation server and declares it as a dependency for the storage server
* Create standalone MemberlistKV service for Ring service to use
* Update the storage server Search and GetStats handler to distribute requests if applicable

pkg/storage/unified/sql/test/integration_test.go

@@ -113,7 +113,7 @@ func TestClientServer(t *testing.T) {
 
 	features := featuremgmt.WithFeatures()
 
-	svc, err := sql.ProvideUnifiedStorageGrpcService(cfg, features, dbstore, nil, prometheus.NewPedanticRegistry(), nil, nil, nil)
+	svc, err := sql.ProvideUnifiedStorageGrpcService(cfg, features, dbstore, nil, prometheus.NewPedanticRegistry(), nil, nil, nil, nil)
 	require.NoError(t, err)
 	var client resource.ResourceStoreClient