Dev replace thumb in Import WMS

Sorry for the reviewers I change the indent of files.

This PR replace the useless thumb image in the list of WMS layers and replace it by a zoom to extent button.

So I add only 2 functions .zoomOnLayerExtent and getLayerExtentFromGetCap
I also replace the use of translate filter by a translate directive when it was possible.

http://mf-geoadmin30t.bgdi.admin.ch/branch/dev_replace_thumb/prod/