This PR adds home screen tethering notification. The notifications
allows user to disconnect tethering from desktop by focusing on
the notification and pressing `KEY_ENTER`
This PR adds also home screen notifications icons in `.png` format.
Icons shall be converted to `.vpi` and used in other tasks regarding
home screen notifications.
This PR provides following changes in notifications:
- notifications were extracted as widget for pop-up-based
locked-screen implementation
- notifications are ListView based implemented
- the most recent notification is displayed on the top of the list
Przemyslaw Brudny