Add support for DHCPv6 client

[troglobit]

Description

A common feature most operating systems support, e.g., OpenWRT.

Additional Information

No response

General Information

Anyone can help out by sponsoring development of new features or contributing pull requests.
Please use this issue for discussions related to the feature.

[troglobit]

CCB: team agrees, this would be a nice feature to have, but aligned with #1109 rather than the IETF yang model.