Migrate to stateless app.App (#17542)

* add request context

* move initialialization to server

* use app interface instead of global app functions

* remove app context from webconn

* cleanup

* remove duplicated services

* move context to separate package

* remove finalize init method and move content to NewServer function

* restart workers and schedulers after adding license for tests

* reflect review comments

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/shared_channel.go

@@ -59,7 +59,7 @@ func getRemoteClusterInfo(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	// GetRemoteClusterForUser will only return a remote if the user is a member of at
 	// least one channel shared by the remote. All other cases return error.
-	rc, appErr := c.App.GetRemoteClusterForUser(c.Params.RemoteId, c.App.Session().UserId)
+	rc, appErr := c.App.GetRemoteClusterForUser(c.Params.RemoteId, c.AppContext.Session().UserId)
 	if appErr != nil {
 		c.Err = appErr
 		return