support image layer in `LayerSwitcher`

[LukasLohoff]

Description

Related issues or pull requests

Pull request type

• [ ] Bugfix
• [ ] Feature
• [ ] Dependency updates
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] Documentation content changes
• [ ] Other (please describe)

Do you introduce a breaking change?

• [ ] Yes
• [ ] No

Checklist

• [ ] I understand and agree that the changes in this PR will be licensed under the BSD-2-Clause.
• [ ] I have followed the guidelines for contributing.
• [ ] The proposed change fits to the content of the Code of Conduct.
• [ ] I have added or updated tests and documentation, and the test suite passes (run npm test locally).
• [ ] I have added a screenshot/screencast to illustrate the visual output of my update.