Implement missing scroll support (not only) for Spring GraphQL

[meistermeier]

The ...FluentQueryBy... classes do not implement/overwrite the limit and scroll functions yet.
This limits the usage from the Spring GraphQL side because it cannot invoke ...limit(..).scroll(..) successfully. The default implementations in FetchableFluentQuery will throw an exception.

Plan is to extract the existing functionality from the PartTreeNeo4jQuery and make it usable also in the context of the ..FluentQueryBy... classes to avoid duplication.