remove angular-leaflet plugin

- remove angular-leaflet
- add vanilla leaflet
- add leaflet fullscreen control
update html templates

- remove <leaflet> custom tag (directive)
- rename map controller to `qgovMapController`
refactor map controller

- use vanilla leaflet (not angular-leaflet)
- prefix model and controller names with 'qgov'
- implement custom icon for clusters
- implement fullscreen control
- implement size map to marker boundaries