Allow change of setting values with rexctl restore

If I make a backup of an instance there can be the case that some settings need to be changed for the new host which isn't possible in the restore command currently and the restore fails after files and database werer successfully restored. Example: engine: up: ... failed to bind host port 10.40.0.20:20004/tcp: cannot assign requested address x Couldn't restore your instance. The instance was behind a reverse proxy with proxy on --bind <old ip>, the old ip doesn't exist on the new machine. Currently you have to accept the failed restore and run rexctl proxy on --bind <new ip> afterwards

Let us set settings via --set when restoring via rexctl Examples: rexctl restore backup.tar.zst --set edge.bind=127.0.0.1:8080 rexctl restore backup.tar.zst --unset storage.endpoint,storage.access_key,storage.secret_key It would validate the settings and apply them after the backup was restored but before the containers are started