This allows us to add there any .uno command and
also get the icon and keyboard shortcut for it.
Use this to add clipboard commands.

Change-Id: Ic42c28add7771f322491e8e7d6df052e3c2c8d75
Reviewed-on: https://gerrit.libreoffice.org/37353Reviewed-by: Maxim Monastirsky <momonasmon@gmail.com>
Tested-by: Maxim Monastirsky <momonasmon@gmail.com>