Add TResult to GraphQLFieldResolver signature

[tgriesser]

Tried out the 16.0.0-rc and noticed the change from return type of GraphQLFieldResolver from any in 15.x to unknown. While this type change is correct, it'd be better if the generic could be specified by a consumer library, for instance if maintaining the previous behavior of any is desired in a library usage.

[linux-foundation-easycla]

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• ✅ Tim Griesser (9a170a0)

[IvanGoncharov]

@tgriesser Thanks a lot.

While this type change is correct, it'd be better if the generic could be specified by a consumer library, for instance if maintaining the previous behavior of any is desired in a library usage.

Totally agree 👍
Also, it should help server-side codegen.

I will release it in the next RC.
I also can add this argument to 15.x.x line, if you need to support both versions in your lib, just create PR against the 15.x.x branch.