Minor updates to the UX for push notifications.

Cleaner toggle design in the notification drop down (toggle icon only with no text will prevent the toggle jumping around because of changes in the text. Now the text is hidden and shown as tooltip instead).

Update the UX for Disabled state. If a user can not Subscribe because their device does not support push notifications, we should hide the subscribe toggle in the notification dropdown completely, and we can update the text of the subscribe button that is in the UCP to tel the user that their device does not support push notifications.