Use area entities in area card for temperature and humidity

[piitaya]

Proposed change

Temperature and humidity entities has been added to area registry (ref : home-assistant/core#135423)
The area card will now use these sensors in priority instead of using the average of all temperature and humidity sensor.
If the entities are not set, it will use the previous behavior.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io