Async, full test coverage, and stability improvements.

Refactor component to async & Major release (#23)

* WIP refactor component to async

* Add const and setup domain

* Add basic tests

* Draft for gihub actions ci

* Relax coverage while we build it up

* Fix throtting condition

* Fixes

* Revert back to call_later due to thread saftery

* Fully remove expire if old

* Better tests for setup

* 90% test coverage

* Fix component domain

* Add badges

* Changelog with breaking changes

* Add code coverage

* Simpify testing matrix

* Coverage badge

* Set high standards for coverage

Pre-release - HACS support and sync setup

Merge pull request #22 from ruuvi-friends/general-cleanup

General cleanup