Add page property that tells if the page is currently selected
Add page property that tells if the page is currently selected

Summary: Useful to be able to visually react to the page having the focus

Reviewers: #kirigami, mart

Reviewed By: mart

Subscribers: plasma-devel

Tags: #kirigami

Differential Revision: https://phabricator.kde.org/D4687

bearsh/kirigami,bearsh/kirigami