support search for UV

[eleanorjboyd]

Add uv as a type of environment supported. For uv it should:

-Discovery of all global Python installs (done via uv)
-Discovery of all Python virtual environments (create via uv, these are just venvs so they should be set)

Make sure different OS types are supported

[KalleDK]

Especially useful if you use UV_PROJECT_ENVIRONMENT as the venv might not be in the workspace

[karthiknadig]

Supported via #263