Shelly migrate to update entity (#78305)

* Add update entity

* fixes

* fixes

* change to CONFIG catogory

* return latest version if no update available

* fixes

* Remove firmware binary_sensors and buttons

* import Callable from collections

* remove ota_update tests

* Update homeassistant/components/shelly/update.py

Co-authored-by: Shay Levy <levyshay1@gmail.com>

* simplify

* fix mypy

* Create test_update.py

* fix isort

* add progress support

* fix styling

* fix update_tests

* fix styling

* do not exclude shelly update test

* bring coverage to 100%

* snake case

* snake case

* change str(x) to cast(str, x)

* simplify tests

* further simplify tests

* Split MOCK_SHELLY_COAP and MOCK_SHELLY_RPC

* fix issort

* fix status test

* fix isort

* run python3 -m script.hassfest

Co-authored-by: Shay Levy <levyshay1@gmail.com>