[MM-34179] app: move cluster registeration to server creation (#17306)

* app: move cluster registeration to server creation

* initserver via fakeapp

* reflect review comments

cmd/mattermost/commands/server.go

@@ -111,6 +111,13 @@ func runServer(configStore *config.Store, usedPlatform bool, interruptChan chan
 		return serverErr
 	}
 
+	// TODO: remove this and handle all required initialization while creating
+	// the server. In theory, we shouldn't depend on App to have a fully-featured
+	// server. This initialization is added so that cluster handlers are registered
+	// and job schedulers are initialized.
+	fakeApp := app.New(app.ServerConnector(server))
+	fakeApp.InitServer()
+
 	// If we allow testing then listen for manual testing URL hits
 	if *server.Config().ServiceSettings.EnableTesting {
 		manualtesting.Init(api)