Add config flow to Russound RIO integration (#121262)

* Add config flow to Russound RIO

* Ensure Russound RIO connection is handled at entry setup

* Add tests for Russound RIO config flow

* Add yaml configuration import to Russound RIO

* Use runtime_data to store Russound RIO client

* Seperate common import and user config logic for Russound RIO

* Update config flow to use aiorussound

* Add MAC address as unique ID for Russound RIO

* Fix pre-commit for Russound RIO

* Refactor config flow error handling for Russound RIO

* Add config flow import abort message for no primary controller

* Add common strings to Russound RIO

* Use reference strings for Russound RIO issue strings

* Remove commented out test fixture from Russound RIO

* Clean up test fixtures for Russound RIO

* Remove model from entry data in Russound RIO

* Clean up Russound client mock

* Clean up Russound test fixtures

* Remove init tests and clean up Russound config flow cases