Namespaces

At the moment all GraphQL types share one global namespace. This is also true for all of the fields in mutation/subscription type. It can be a concern for bigger projects which may contain several loosely-coupled parts in a GraphQL schema.

I tried to describe this feature in detail in following article (which also includes motivation and different use-cases):

[GraphQL Namespaces Proposal](https://medium.com/@oleg.ilyenko/graphql-namespaces-proposal-2a097ce81d2a)

After posting this it, I saw interest from different people within the GraphQL community, so I decided go one step further and open this issue in order to suggest inclusion of this feature in the spec and start a discussion around it.

I suggested particular syntax & semantics for the namespaces, but I myself still not 100% sure that it can be used as-is. I hope, that as we discuss it, we would come up with better syntax and semantics (or maybe even entirely different feature) that better fits existing language features and covers described use-cases.