PhoshHome: Use PhoshLayerSurface signals and props to handle resizing

This fixes the issue with disappearing bottom bar when output dimensions change and is actually more in line with what we wanted to achieve there.

added 15 commits

• 2977bd1e...e3dd0722 - 14 commits from branch Librem5:master
• 46fabd13 - PhoshHome: Use PhoshLayerSurface signals and props to handle resizing

Compare with previous version

changed the description

merged

thanks.

mentioned in issue #311 (closed)