Upstream as of 2f484537

This is basically the same as !24 (closed) but

• not WIP
• no non upstream commmits
• test plan according to !24 (closed)
• two commits more recent so we get the libav/ffmpeg build bug fix as well

Testing plan:

nitrogen board (with phosh at factor 2 scaling)

• rotation
• touch input
• auto maximazation

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)

(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
• xdg app switching

qemu (at scale == 2)

• rotation
• librem5 like geometry