Update Scene Editor

[karwosts]

Proposed change

Updates to scene editor as proposed: https://www.figma.com/design/TJ1yBZUyOWQtLmugi239BU/HA-12?node-id=0-1&node-type=canvas

Continuation from #20094

Extra help testing would be appreciated.

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

[wendevlin]

Thank you @karwosts 🎉 This improves the UX a lot.

I have some desing improvements in mind, which I will add in another PR.

• live / review mode toggle on mobile must become smaller
• Improve spacing
• Instead of empty devices/entities show some info
• Deduplicate entities heading.