Add easier customisation for building groups of projects in gradle

[spacey-sooty]

Goofy ahh https://github.com/wpilibsuite/allwpilib/blob/main/.github/workflows/tools.yml#L37

[sciencewhiz]

Just publish will publish all projects. But that was done intentionally to avoid building things like the gui tools that aren't needed for downstream tools to shorten build time.

[spacey-sooty]

It'd be nice if there was a better way to do that then. Maybe a flag like CMake has to avoid GUI tools?

[rzblue]

I don't think this is really needed