Allow themeing of media control card

[spacegaier]

Breaking change

Proposed change

1. Allow themeing for media control card. Was already technically possible, but had no editor support plus did not work for previewing (too restrictive checks in updated()).
2. Explicitly state in the card config interfaces where themes work (previously some relied on the generic [key: string]: any; in LovelaceCardConfig.
3. Moved theme picker for picture card and picture entity card out of the side-by-side since there were already two other fields in the row for the actions and those need more space to e.g. provide a URL or navigation target. Was quite crowded.

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: Add theme support to media control card home-assistant.io#16282

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