Service config - Accept/Reject/Unconfirmed Flag

[linux4life798]

Services should be able to give the rest interface feedback about whether it accepts or rejects the config for a device. When the service starts up, it should be able to see if it previously accepted or rejected a certain config.

Certain services that manage registration, such as lorawangw and lorawan, require configs that may collide with each other(other device's configs). Only one device's config must succeed.

This proposed change would fix the current race condition that occurs when these types of services startup.
Additionally, it would give the website a clear Good or Bad for the linked service, which it could then allow it to show a warning/error for a certain service.

Details

• The interface for flags probably should not alienate very simple services that do not want to use it. Thus, there should be some REST side default action, like auto accept if a status is posted, simply stay in unconfirmed state, or add a fourth state that indicates the config was observed.

[linux4life798]

Would fix https://community.openchirp.io/t/security-flaw-in-lorawan-gateway-service/34