Display entities without area in summary dashboard

[piitaya]

Proposed change

Fixes #27787

1. Adds support for no area, no floor and no device in entity filter by using null option.

The following filter will match with entity unassigned to an area.

area: null

2. Use this new filter to adds entities/devices unassigned to an area to the summary dashboard (light, climate and safety).

A new section is added below the floors and areas.

Note : the media players views from the home strategy also supports this unassigned entities section.

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