Migrate BraviaTV to new async backend (#75727)

.coveragerc

homeassistant/components/braviatv/__init__.py

homeassistant/components/braviatv/config_flow.py

homeassistant/components/braviatv/const.py

homeassistant/components/braviatv/coordinator.py

homeassistant/components/braviatv/entity.py

homeassistant/components/braviatv/manifest.json

homeassistant/components/braviatv/media_player.py

requirements_all.txt

requirements_test_all.txt

tests/components/braviatv/test_config_flow.py