Enable removing multiple devices at once
Summary:
With the device list only allowing one item to be selected, removing
many devices takes a lot of clicking. Allowing multiple selection
solves that with a familiar UI pattern.
Reviewers: VDG, Plasma, ngraham
Reviewed By: VDG, ngraham
Subscribers: ngraham, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D24110