lib: Add PARENTAL_NOT_LAUNCHABLE quirk to prevent launching apps

As well as filtering installation of applications, parental controls need to prevent launching banned applications which are already installed on the system (perhaps for other users). While installation is controlled through OARS ratings, launching is controlled via a blacklist.

Add a new quirk to GsApp for apps which should not be launchable due to violating the blacklist, and check for it on the details page.

It is up to vendor plugins to implement the policy to set this quirk on apps.

Signed-off-by: Philip Withnall withnall@endlessm.com