WIP: Merge master with input support

This branch will bring input-method and text-input support to the Librem5.

This will unblock virtboard!21 (closed) and help virtboard#3 (closed) .

Testing plan:

nitrogen board (with phosh at factor 2 scaling)

• rotation
• auto maximization
• automatic virtboard popup when switching focus around
• virtboard typing with preedit

amd64 (with phosh at scale == 1 and two outputs (LVDS and HDM1))

• rotation
• moving of surfaces between outputs
• auto maximazation
• xdg app switching
• brighness control
• nightlight
• restarting phosh several times
• running phosh against the unpatched wlroots
• check rootston's power consumption using powertop (~15mW, peaks at ~70mW)
• automatic virtboard popup when switching focus around
• virtboard typing with preedit

(note that touch input won't work out of the box due to https://github.com/swaywm/wlroots/issues/940

rootston-on-X at scale factor 2

• auto maximization
• phosh app switching
• automatic virtboard popup when switching focus around
• virtboard typing with preedit

qemu (at scale == 2)

• rotation
• librem5 like geometry
• phosh app switching
• automatic virtboard popup when switching focus around
• virtboard typing with preedit