Add scenes and scripts as buttons in footer of area cards

[balloob]

Breaking change

Proposed change

Generated Lovelace will add scripts and scenes that are linked to an area as action buttons at the bottom of the entities card for that area.

Initially I wanted to do this with chips but I realized that it required a new header-footer which caused this branch to be stale since the beginning of the month.

This is to wrap the first step up, we can iterate on it after this.

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