Don't use the api.alsa.soft-mixer option to disable the path selection
but make a new api.alsa.disable-mixer-path.
Disabling the path selection might leave cards unusable after suspend,
so a separate option is a better idea.
See #4311
Collect the list of object properties into a single place.
Group properties in the index based on the object type. Consider
"Monitor" as a separate object type, as it's generally configured
separately.
Add something about Port, Link, and Client properties. Just explain some
of these as they're fairly technical, so just link to API docs.
