This makes it possible to search layer names in the
`Named Layer Selection` node as well as boolean
modifier inputs that are marked as a `Layer Selection`.
The layer selection UI is slightly updated:
* Use a slightly larger default width for the
`Named Layer Selection` node.
* Use the layer icon in the field that search for layer names.
* Use `Layer` placeholder string
Pull Request: https://projects.blender.org/blender/blender/pulls/137273
69a722cee5