Revert "Korganizer: Add quickview for person collections"

This reverts commit e252dae1d9ef3d07ebd3fee788142f3f6a85f89e.
Make it possible to update personnodes for the reparenting model

* show subcols again
* add tests to make sure that update works

KOLAB: #3743
Korganizer: Add quickview for person collections

KOLAB: #3054
Merge remote-tracking branch 'kolab/kolab/integration/4.13.0' into kolab/integration/4.13.0

Conflicts:
	korganizer/views/collectionview/controller.cpp
ReparentingModel: Simplified and clearer update mechanism.

Instead of replacing the complete node, which was just a workaround to the
reparentingmodel not knowing anything about the personnode, we delegate that
work to the node itself.
CollectionFilter: QModelIndex::child doesn't work on an invalid index
ReparentingModel: Fixed filtering in model

dataChanged still needs to be emitted (because the data changed), and we can't
use the move signals since QSortFilterProxyModel doesn't handle them.
CalendarSelection: Sort search folders at the end.
CalendarSelection: Only show the quickview button on the search collections.
Proper name for invitation folders.
Declined/OpenInvitations calendars: Avoid remote searches

They don't work anyways so avoid the additional cost of a remote search try.
CalendarSupport/KCalPrefs: Store category colors in tags.