Use  interceptor and jquery events to catch status of requests

Since we use $http interceptor in gaNetworkStatus. I think we can use the same method for the managemant of wait cursor.

Test [here](http://mf-geoadmin3.dev.bgdi.ch/dev_wait/) 

Compare without spaces https://github.com/geoadmin/mf-geoadmin3/pull/1671/files?w=1 because there was a false indentation in SearchDirective

Fix #1668  

Btw: the bug described in https://github.com/geoadmin/mf-geoadmin3/issues/1695 is even more annoying in the PR. With this PR, you can create some kind of infinite loop, where the app constantly switches between offline and online mode for a long time (20 seconds sometimes).