Extend manifest labels test case with manifest_lists

[vsedmik]

Problem Statement

1. Manifest labels, annotations and other flags were added to manifest lists too (previously they were added to manifests only). After container-type repo sync they should be indexed and returned by API.
2. Also the labels and flags should be indexed during upgrade from 6.16 to 6.17.
3. We are going to have a new-style approach to the upgrade scenarios.

Solution

1. We already have a test case to check the fields in manifests. This PR extends the test case to check the same in manifest lists too.
2. We already have similar test case in upgrade scenarios. This PR extends the test case, and
3. makes it a new-styler using the share_resource approach.
4. Here we also update the CODEOWNERS file with the new upgrade files.

Related Issues

https://issues.redhat.com/browse/SAT-27490

PRT test Cases example

Requires
Katello/katello#11172
SatelliteQE/nailgun#1240 (merged)

trigger: test-robottelo
pytest: tests/foreman/api/test_repository.py -k synchronize_docker_repo_with_manifest_labels
Katello:
  katello: 11172

For the new-style upgrade scenario we need to wait for the 11172 being packed in next snap.

trigger: test-robottelo
pytest: tests/new_upgrades/test_repository.py -k test_container_repo_sync
env:
  BROKER_SSH_BACKEND: hussh

[vsedmik]

trigger: test-robottelo
pytest: tests/foreman/api/test_repository.py -k synchronize_docker_repo_with_manifest_labels
nailgun: 1240
Katello:
katello: 11172

[Satellite-QE]

PRT Result

Build Number: 9299
Build Status: UNSTABLE
PRT Comment: pytest tests/foreman/api/test_repository.py -k synchronize_docker_repo_with_manifest_labels --external-logging
Test Result : ========= 167 deselected, 180 warnings, 2 errors in 4768.37s (1:19:28) =========

[Satellite-QE]

PRT Result

Build Number: 9300
Build Status: UNSTABLE
PRT Comment: pytest tests/foreman/api/test_repository.py -k synchronize_docker_repo_with_manifest_labels --external-logging
Test Result : ========= 167 deselected, 180 warnings, 2 errors in 5364.90s (1:29:24) =========

[synkd]

Reviewing specifically for the change to the new upgrade format, everything looks good there.