Add unit tests!

[NotWoods]

Summary

Sets up some infrastructure for unit testing repository classes!

Screenshots

N/A

Link to pull request in Documentation repository

Documentation: home-assistant/companion.home-assistant#

Any other notes

https://developer.android.com/training/testing/local-tests https://mockk.io/ https://developer.android.com/kotlin/coroutines/test

[jpelgrom]

Thanks for updating these because everything changed (and patience while the original PR sat ignored for months), but if we want to merge this and take it seriously, the CI runs for PRs should be updated to run tests.

[jpelgrom]

Closing as this seems abandoned