Moving serial settings to a separate crate

[ryan-summers]

This PR fixes #808 by creating a new crate for serial settings and storage.

From the serial console:

Input was empty?

> help
AVAILABLE ITEMS:
  dfu
  service
  reboot
  factory-reset
  list
  get <item>
  set <item> <value>
  help [ <command> ]

> dfu
Reset to DFU is not supported on this device

> service
Service data not available

> list
Available items:
/broker: "test" [default: "mqtt"]
/id: "04-91-62-d2-a8-6f" [default: "04-91-62-d2-a8-6f"]

[ryan-summers]

@jordens I'm curious to see if you have any thoughts with the current design. It's definitely not perfect, but I think it's at a decent point for now. I'm going to poke at integrating it into Booster to see how it goes.

[ryan-summers]

@jordens Some questisons/comments on the design. Overall, I think we're pretty close to being able to publish this as something. Do we want to keep it in the stabilizer repo for now, or split it into (yet another) repo?

[ryan-summers]

@jordens Some questisons/comments on the design. Overall, I think we're pretty close to being able to publish this as something. Do we want to keep it in the stabilizer repo for now, or split it into (yet another) repo?

Two last comments/discussions left above, but otherwise I think things here are at a nice state. Ping on the question above as well.

[jordens]

Let's split it once you want to use it on Booster. Is that now?

[ryan-summers]

Let's split it once you want to use it on Booster. Is that now?

Meh, there's no huge rush to move it onto Booster yet, so maybe we just let it live here for the time being. We can break it out into a separate crate when we feel like it's mature enough.