Feedback / Draw interaction improvement

This adresses https://github.com/geoadmin/mf-geoadmin3/issues/1929

Thanks to @oterral , this is a better alternative to https://github.com/geoadmin/mf-geoadmin3/pull/1934

Please review and [test here](http://mf-geoadmin3.dev.bgdi.ch/dev_focus_popup)