CB migration assistant

name: CB migration assistant
about: A method to migrate to CB

When users need to migrate from a file-based json configuration to the Configuration Backend, or to migrate between the supported databases, it would be useful if Kea provided some tool to support this.

Possible methods could: The implementation of two new CB commands ie:

remote-server4-config-get
and
remote-server4-config-set

Or alternatively the enhancement of the kea-admin tool to provide this functionality.

RT #17095
RT #20167 2023-04-19 subscriber queue closed
RT #21508

Requested migrations: MySQL -> Postgres, also config to MySQL, config to PostgreSQL.