Cockroach-specific implementation of EdgeQL

[acalvino4]

I love the developer experience of EdgeDB, but also the resilient architecture of Cockroach. If the two could be combined, I think we'd have the true ultimate database.

As noted on a similar request (edgedb/edgedb#3403) in their issues, what this essentially involves is a separate implementation of their query language, EdgeQL.

They do note it is not a simple drop in layer on top of any postgres instance (and on top of that, cockroach, while close in query language to postgresql, does have some differences), so it's probably not trivial. Could maybe even use their code as a starting point.