waylandsink: properly implement full screen wayland shell window

This makes the sink properly fullscreen by default (configurable
via the 'fullscreen' property). No other screen elements such as
weston panel are visible, which makes composition faster (and is
a much saner definition of fullscreen).

BUG: 142883165
Change-Id: Icd384e817ecea890716b3b1e55983acdc3719b87
4 files changed