Fix Move To Trash command for virtual collections
Summary:
When current folder is a virtual collection, the Items in it may belong
to multiple different resources and as such have different Trash folders.
This change makes KMTrashMsgCommand aware of this fact and to handle
this case correctly by resolving parent collections of all selected
messages.
Test Plan:
Tested against the Unified Mailboxes Agent (currently loving in
dev/unified-mailboxes branch) which has virtual collections.
Reviewers: mlaurent
Reviewed By: mlaurent
Subscribers: kde-pim
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D14465