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/scheme_test.go

@@ -770,7 +770,7 @@ func TestUpdateTeamSchemeWithTeamMembers(t *testing.T) {
 		th.App.SetPhase2PermissionsMigrationStatus(true)
 
 		team := th.CreateTeam()
-		_, _, err := th.App.AddUserToTeam(team.Id, th.BasicUser.Id, th.SystemAdminUser.Id)
+		_, _, err := th.App.AddUserToTeam(th.Context, team.Id, th.BasicUser.Id, th.SystemAdminUser.Id)
 		require.Nil(t, err)
 
 		teamScheme := th.SetupTeamScheme()