Fix kglobalaccel integration

There is a kconf_update for migrating the old khotkeys shotcut to kglobalaccel. It registers a shotcut with kglobalaccel

However, on a fresh installation there is no old shotcut to migrate and no shortcut is registered

Install an appropriate desktop file to the kglobalaccel location so that it picks up the shortcut on a fresh install

(cherry picked from commit 24620fa8)