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>

app/plugin_shutdown_test.go

@@ -57,7 +57,7 @@ func TestPluginShutdownTest(t *testing.T) {
 				plugin.ClientMain(&MyPlugin{})
 			}
 		`,
-		}, th.App, th.App.NewPluginAPI)
+		}, th.App, th.NewPluginAPI)
 	defer tearDown()
 
 	done := make(chan bool)