Sxmo allow switching between pulseaudio and pipewire

Theres an audio regression with v22.12 on the poco f1 running sxmo: #1821 (closed)

Joel diagnosed the problem as Sxmo using pipewire instead of pulse (as used by phosh and plasma mobile). Since the issue doesnt appear on those UIs, I have written a couple of patches here to add the ability to use sxmo with pulseaudio.

Please see the commit messages for the commits for more context. After building these two packages, users can switch to pulseaudio with doas apk add sxmo-common-pulse.

I cannot get audio to work in calls (the other side cannot hear me) on the poco f1 with these patches. I need help from someone that knows sdm845 and pulseaudio better than me. Hope someone can build off my work here.