* Make async_get_device connections Optional, default None
* Remove unnecessary async_get_device connections arg usages
Some of these were using an incorrect collection type, which didn't
cause issues mostly just due to luck.
* Use tests.async_mock instead of asynctest
* Remove unnecessary existence check
* Improve songpal service registering
* Add tests
* Seperate device api from entity api
* Improve disconnect log messages
* Improve tests
* Rename SongpalDevice to SongpalEntity
* Improve reconnecting
* Remove logging and sleep patch from tests
* Test unavailable state when disconnected
* Rename SongpalEntity.dev to _dev
* Add quality scale to manifest