Do not render "No Area" in device table to reduce clutter

[spacegaier]

Depends on PR #7985 for sorting logic.

Breaking change

Proposed change

Currently the UI fills the "Area" column of the devices overview with "No Area" if none was assigned. That makes it very hard to find the ones that you still have to assign. Plus in the entity overview we do not do that either.

This PR removes the auto-filled "No area". Once the above mentioned prerequisite PR has been merged, having the area value as "undefined" is no longer an issue for sorting as well.

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