Add FM auto scan feature

[barbeau]

Is your feature request related to a problem? Please describe.
Many FM radios have an auto scan feature that you can enable where it will scan to the next station, play for X amount of time, and then scan to the next station, play for X seconds, etc. unless you interact with the radio to stop on a station you like.

Describe the solution you'd like
We could implement something similar in MUSER. 20 seconds long default may be nice. There are also variants where we could start playing in the middle of the track (because classical and other music may have slow starts), or intelligently find peaks and start there.

Describe alternatives you've considered
Do nothing - leave as is.