Persona Dialog modified. Search supports Firefox Theme URL.
Added display of installed theme on personalization dialog.
Fixed category buttons. Added SOLID as category. Removed
invalid/duplicate results.

Change-Id: I603c0c292fe5c3e380553b9a2eaab6f4bc0683e1
Reviewed-on: https://gerrit.libreoffice.org/23385Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>
Tested-by: Jenkins <ci@libreoffice.org>