Add mechanism for generating public query functions and types

[fmoor]

Currently edgeql-go generates private query functions and return types. The user can export these types but it requires a few lines of code for each query. There should be a way to make the generator generate public instead of private functions and types.

Maybe this should be configurable on a per query basis?

[chirino]

I would default to being public, if a user really wants to keep it private he can place it under an internal directory so that it's public to external packages.

[fmoor]

I would default to being public, if a user really wants to keep it private he can place it under an internal directory so that it's public to external packages.

Public by default seems reasonable, but I think there should still be a way to make them private to a package. In a large enough project it is reasonable to want to restrict some things more than just internal/.