pipewire: Add allowed sample rates
These are all the sampel rates that my audio interface supports.
48kHz is set as the default since this is apparently the industry
standard, but apparently it doesn't sound much different at all from
44.1kHz.
Because of this, I may set the default to 44.1kHz, but this may cause
extra processing since pipewire would need to resample audio from
games, videos, and pretty much anything that isn't music down from
48kHz to 44.1kHz.