Add ddns-update-on-renew ddns-use-conflict-resolution support to CB
Config backend does not support the following DDNS behavioral parameters. They need to be added.
ddns-update-on-renew ddns-use-conflict-resolution
This work could be combined with related #225 (closed) which would add TTL calculation knob(s) and a knob to suppress DHCID generation when conflict resolution is disabled #455 & #2276 (closed). This ticket could be used to add the knobs through to CB and the schema(s), implementing the behavior would be done in their respective tickets.