USB/flash clear/save behavior w.r.t. default changes

[jordens]

Once things have been saved to flash (also implicitly through e.g. clear), then changes in Default are not propagated. This makes the behavior with an empty flash (that has never seen clear) different from the one after clear. Usual expectation is that clear restores behavior to "what it was before/initially", arguably including transparent propagation/activation of changes to Default with app updates.

The proposed alternative is to use remove_item in current clear and #860

#857 (comment)

[ryan-summers]

@jordens Based on my understanding, if you change a Default in the application and re-run the clear command, you will receive the new Default value. Is this specifically what is not desired?

I'm not entirely seeing the difference between an uninitialized flash and one that is cleared. Yes, it will have initial values in it that may or may not be Default, but the proposed change to use remove_item and the current implementation wouldn't have any different effect on the clear command or operation of the device.

[jordens]

I'd see the additional clear required as an work around.

The behavior is different. With the proposed change clear followed by app update also updates to new defaults (like sucessive app updates without ever touching USB).