[6.14.z] use one fixture instead of multiple and remove problematic one

[Satellite-QE]

Cherrypick of PR: #13107

Problem Statement

Hosts-Content component -> CLI tests were failing with AttributeError because of fixture module_gt_manifest_org which is being used inside moduled scoped fixture rh_repo_gt_manifest of repository.py

failed on setup with "AttributeError: '_io.BytesIO' object has no attribute 'filename'"

The fixture rh_repo_gt_manifest simply creates new org with GT menifest, create rhst repo, sync and return the respective repo. Rest of fixtures from test module uses module_sca_manifest_org which creates module org with menifest.
The above setup were problematic.

Solution

Collect scattered fixtures into single module scoped fixture and use it.

Related Issues

No

[damoore044]

trigger: test-robottelo
pytest: tests/foreman/cli/test_contentaccess.py -k 'test_positive_list_installable_updates or test_positive_erratum_installable or test_negative_unregister_and_pull_content'