Migrate functions to app package (#5106)

* Refactor and move session logic into app package

* Refactor email functions into the app package

* Refactor password update into app package

* Migrate user functions to app package

* Move team functions into app package

* Migrate channel functions into app package

* Pass SiteURL through to app functions

* Update based on feedback

app/notification.go

@@ -542,7 +542,6 @@ func ClearPushNotification(userId string, channelId string) *model.AppError {
 }
 
 func sendToPushProxy(msg model.PushNotification) *model.AppError {
-
 	msg.ServerId = utils.CfgDiagnosticId
 
 	tr := &http.Transport{