Move remaining keys to `setup.cfg` (#65154)

* Move metadata keys

* Move options

* Delete setup.py

* Remove unused constants
* Remove deprecated test_suite key

* Improve metadata

* Only include homeassistant*, not script*
* Add long_desc_content_type
* Remove license file (auto-included by setuptools + wheels)

* Add setup.py

Pip 21.2 doesn't support editable installs without it.