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

api/slackimport.go

@@ -413,7 +413,7 @@ func SlackUploadFile(sPost SlackPost, uploads map[string]*zip.File, teamId strin
 }
 
 func deactivateSlackBotUser(user *model.User) {
-	_, err := UpdateActive(user, false)
+	_, err := app.UpdateActive(user, false)
 	if err != nil {
 		l4g.Warn(utils.T("api.slackimport.slack_deactivate_bot_user.failed_to_deactivate", err))
 	}