make _set_feature_modules to return ModuleType objects

[DaniBodor]

see #492 (comment)

in query.py
# TODO: I would prefer if _set_feature_modules would return a list of ModuleType instead of str,
# but this leads to an exception in the pool function in QueryCollection.process, that I don't know how to solve.
# Tests are currently passing ModuleTypes directly, which is clearer than passing strings
# and is the reason I am allowing both input types.

[github-actions]

This issue is stale because it has been open for 30 days with no activity.