Provide internal type mapping for GraphQL types from schema about ariadne

[rafalp]

Thinking quick here, but ariadne.contrib could include validators or linters that would compare the "Python-land" against the GraphQL schema. Eg. we could take a return type from resolver function and verify that this type is accepted by field's scalar.serialize. Or, if resolver if for field returning object, we could verify that object's fields resolvers accept the type returned from parent. Same for arguments or inputs.

Not perfect, but another safety net in projects that need it. And it could actually do a lot.

And for projects that really need to keep everything tight, future Ariadne GraphQL Modules release will be code-first out of the box.