Description of problem:
There is no option to delete missing puppet modules that are not available anymore in the upstream repository. The result is that the number of puppet modules is growing, consuming space and becoming unmaintainable with the available_puppet_modules query.

This is especially important when Sat6 is connected to a CI environment where new builds of puppet modules are updated and changing very frequently. And with every build getting a higher version number and generated e.g. 50 modules the amount of puppet moduels grows very soon in 1000+ scales.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Create puppet directory repository
2. Sync repository
3. Delete modules from repository
4. Sync repository again

Actual results:

Expected results:
Deleted modules are not available anymore

Additional info:
Related to pulp directory importer does not support remove_missing
https://bugzilla.redhat.com/show_bug.cgi?id=1131146