Codegen: exclude unnecessary type classes

[Gavrilov-Ivan]

Hello

Currently dgs-codegen has settings parameter generateDataTypes with 'all-or-nothing' logic: generate classes for all types in schema or not generate at all.
If you have a big schema with huge amount of types but include a few queries only you will get classes for a whole scope of types even if included queries don't use them.

It will be nice to have an ability to generate only the types required according to includeQueries/includeMutations/includeSubscriptions as it already done for input types (the same way or with additional settings parameter).

[srinivasankavitha]

Thanks for the feature request. We can look into adding that in the future.