Expose inner value of GraphQLResponse.

[RyogaK]

In my use case, I need to parse the GraphQLResponse from Juniper’s response and record it as structured logs. While GraphQLRequest has a public (pub) internal structure, but the internals of GraphQLResponse are not accessible, so currently, I have to serialize it once and then re-parse it as a string. This intermediary processing is cumbersome, and I would like to directly access the internal data of GraphQLResponse.

[LegNeato]

Thanks for the change! Perhaps it is better to have an into_result function to mirror the from_result function?

I would also love a simple test that uses the function so we can make sure to not regress accidentally.