Replace the handle with a button widget.
Also remove the unused PendingElement mixin.
Bug: T178387
Change-Id: Iec3afea6c6a8fdb49e17750af7bada42b7ed4b70
Introducing stylelint with configuration rules compliant to
Wikimedia CSS Coding Standards 'stylelint-config-wikimedia', nullifying
some for now and making majority pass.
Change-Id: I2c4acee41c9b56d9b00e2a2c5b7ab0ab5de454ce
Add a global-wiki 'mark all as read' to the Special:Notifications page.
The 'mark all as read' will makr all notifications in the given
wiki. The context of the wiki changes when filters are chosen,
and so the message of the button changes as well.
Bug: T115528
Change-Id: Ibd9dcdf7072d6cbc1a268c18e558e6d0df28f929
