Rethink shared state and how it triggers various threads.

[pritamghanghas]

At a minimum this will require some more documentation like why wifi_scan is triggered in bluetooth advertisement processor

• Comments added to this class to clarify. Possibly changing the class name too.
• Triggering advertisement from some of the wifi related characteristics
• See if the threads are being trigger correctly and if all of them are even required.

_Originally posted by @marvinmarnold in https://github.com/NebraLtd/hm-config/pull/174#discussion_r821072265_

[shawaj]

IIRC we originally did a scan at advertisement so that the results could be cached and ready for when connected.

That was a while ago though so maybe no longer relevant