Pull out react-grab primitives into its own @react-grab/primitives package

Many applications could leverage the battle-tested primitives of react-grab, but without having to add the CLI dependencies. What do you think about pulling out the primitives into a @react-grab/primitives library that could be lightweight and more easily used for general applications?

This feels like a good step in the right direction for this RFC as well

I'm happy to make the contribution if you prefer! Thank you