this should only be in the `parsing_representation.SubModule` class (yes sorry for that stupid submodule name, but we have reasons for that). `SubModule` is only the top level thing, where as `Scope` is everything. The reason why this makes sense is that Python allows `from __future__` imports only on a global level and on top - which means the module level.

also rename to `has_explicit_absolut_import`.
and also remove the caching, as long as it's no bottleneck, we're not optimizing.