Add --cmake-only-configure option

[chapulina]

I saw there's a --cmake-force-configure option, but I didn't see an option that would allow me to run just the configure step for a package, and skip building. This would be helpful while iterating on the configuration.

My use case is for building a single package, and I imagine this option may be problematic when building multiple packages.

[kunaltyagi]

I felt the need for this today. Made a PR :)

Let's hope it gets accepted soon 🤞🏾

[julyfun]

it's useful when you just want to quickly index your project