Ability to write Kea config (config-set + config-write)
Sooner or later, Stork will need the ability to write Kea's config file to disk. Couple scenarios where it would be handy:
- checkers now report issues. With config-write available, we could think about "fix it for me" button.
- we talked about HR migration from config file to DB.
- we talked about migrating subnet/shared networks from config file to CB.
- enabling higher logging levels for debugging
- many more...
There are many ways how to slice this, so design is needed for sure. Personally, I think this ticket should cover design phase and maybe code for the agent ability to do the write, but without any UI elements. A stepping stone for future work.