Add support for dark_icon and dark_logo

[ludeeus]

Proposed change

Allow add-on authors to add a dark_[icon|logo].png file that will be requested when the user has dark mode enabled in the frontend.

If that file does not exist it will fallback to the regular [icon|logo].png file

Type of change

• [ ] Dependency upgrade
• [ ] Bugfix (non-breaking change which fixes an issue)
• [x] New feature (which adds functionality to the supervisor)
• [ ] Breaking change (fix/feature causing existing functionality to break)
• [ ] Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request: https://github.com/home-assistant/developers.home-assistant/pull/1359
• Link to cli pull request:

Checklist

• [ ] The code change is tested and works locally.
• [ ] Local tests pass. Your PR cannot be merged unless tests pass
• [ ] There is no commented out code in this PR.
• [ ] I have followed the development checklist
• [ ] The code has been formatted using Black (black --fast supervisor tests)
• [ ] Tests have been added to verify that the new code works.

If API endpoints of add-on configuration are added/changed:

• [ ] Documentation added/updated for developers.home-assistant.io

[pvizeli]

Have to wait until https://github.com/home-assistant/supervisor/pull/3623 is merged because the endpoints moved

[ludeeus]

Not usable without a core and a frontend change anyway

[frenck]

Sad to see this one closed to be honest :(