HaikuDepot: Fixed regression: selecting featured packages

Since the fVisiblePackages list in MainWindow is now also filtered by
featured packages, and since the "featured" status of packages is collected
asynchronously, the list needs to be updated in the package changed
notification. Also, the package should only be added to the featured packages
view if it is now in the visible list. Other filter criteria would not be
taken into account otherwise. Fixes #11663
HaikuDepot: Clear package info view if package not listed

If the visible packages list does not contain the currently showing package
anymore after filter parameters have changed, clear the package info area.
This also means that when installed packages are turned off, which means
a package will disappear from the list after being installed, the package
will no longer keep showing in the info area. This situation is less likely
with the change that installed packages will now show by default and the
user has to explicitly turn them off.