Srv_getPackagesForUid doesn't use app whitelisting

[Magissia]

Current implementation of "Srv_getPackagesForUid" in XPrivacy ignore application white listing, allowing apps to either gather information of all your installed applications from it, or crash if the application was not made to handle the fact it may be unable to retrieve the data it should have retrieved when restricted.

In the best of the worlds, we could always restrict it and don't care if it doesn't use the app whitelisting, but some DRMs require to retrieve package information of the applications they are supposed to guard, and some decided "Srv_getPackagesForUid" was the best way.

I am suggesting to look if it is possible to make "Srv_getPackagesForUid" use the app whitelist, if it's a too huge performance hit, maybe restrict it with a per-app quirck (or global for adventurous users).