main/postmarketos-base-ui: add pipewire and wireplumber plus related packaging cleanups

Most UIs already depend on it in one way or another (plasma specifically, phosh through xdg-desktop-portal-wlr), and seems like we're no longer getting pipewire-pulse installed together with it. So should be safe to have, and gets us closer to a good camera experience

Fixes #2785 (closed)