Entrypoints design for projects declaring components

[henryiii]

Orignal proposal:

[project.entry-points."cmake.root"]
findname = "pkg.some.data.folder"

[project.entry-points."cmake.module"]
anything = "pkg.some.data.folder"

[project.entry-points."cmake.prefix"]
anything = "pkg.some.data.folder"

# Example usage
module_dirs = importlib.metadata.entry_points(group="cmake.root")
packages = {ep.name:importlib.resources.files(ep.load())
            for ep in module_dirs}
cmake_args = [f"-D{k}_ROOT={v}" for k,v in packages]

Dirs should contain an __init__.py.