tyoescript-resolvers - Support customising mapper for List types

[TastyPi]

Is your feature request related to a problem? Please describe.

graphql-js supports AsyncIterables for array query resolvers graphql/graphql-js#2757

AFAICT, there is not a way to configure graphql-codegen to return AsyncIterables for array resolvers.

Describe the solution you'd like

Either introduce something like an ArrayField type which supports everything graphql-js supports:

type ArrayField<T> = T[] | AsyncIterable<T>

(this might not be as generic as it could be, I haven't checked)

Or allow a way to define a mapper for arrays (maybe there is a way to do that already, I couldn't find any documentation for it).

Describe alternatives you've considered

I could modify the generated code, or give up on codegen, or not use AsyncIterables.

Any additional important details?

No response