[5.5.0] - 2023-01-20

- Add new backend "ubus" for querying `/bin/ubus`.
- tests: Allow ubus-cli mock to load json data for tests.

- lan+wan: refactor querying ubus from lan & wan backends.
- networks: Change severity of log message during detection of network bridges
  from "warning" to "debug". It will no longer spam system log during normal operation
  of foris-controller with message
  "WARNING:foris_controller_backends.networks:No anonymous section 'br-<bridge_name>' found among network devices.".
- lan: Make fetching dhcpv6 leases more resilient to unexpected values.