Managing the transition from old implementation to new:
* A version number is exported from skins.minerva.scripts to
tell dormant code added to Echo in I09c27a084100b223662f84de6cbe01bebe1fe774
to begin running.
* A skinStyle is added for the new `ext.echo.mobile` module.
`mobile.notifications.overlay` will soon cease to exist but is kept registered for
backwards compatibility reasons
- Drop ev.preventDefault call from onSkinClick - it is no longer necessary and will ensure
notifications overlay closes when shield is clicked while it is open.
Integration:
* A server side hook SkinMinervaReplaceNotificationsBadge allows Echo to replace
the current Minerva notification badge
* A to-be-created client side hook is subscribed to to deal with the navigations drawer
like functionality using the mainMenu code
* id and class names are added to the container for the NotificationBadge for compatibility with
ext.echo.init in Minerva's desktop mode (it will work like Vector)
See I09c27a084100b223662f84de6cbe01bebe1fe774 for understanding the bigger
picture.
Depends-On: I09c27a084100b223662f84de6cbe01bebe1fe774
Bug: T221007
Change-Id: I4c11f1b241d629e1b294ebaec17472fbf944f8c7
