[6.15.z] Errata-UI: Fix test_positive_host_content_library

[Satellite-QE]

Cherrypick of PR: #14926

Problem Statement

• outdated setup using old fixtures and deprecated methods.
• Resolved conflict with newly introduced case from (recently merged commit).
  ^ Above commit renamed test_positive_content_host_library to test_positive_check_errata,
  and rewrote as a fundamental quick check of New Host > content > errata details.
  So test_positive_check_errata it could be a new smaller case, I gave it a unique :id, and made tier2 importance.
  I think it's still good to retain this PRs changes for test_positive_host_content_library, which is searching and reading the full errata tables displayed in UI, for new host and legacy chost.

Solution

• rename to test_positive_host_content_library, to reflect that we'll also be checking new host > content > errata tab.
• needs Airgun#1374: add support for new host errata table fetch, and fix legacy chost errata search.
• probably depends on [stream] fixes for combined session failures, Errata UI #14822 getting merged first- includes important fixture updates

PRT Case

trigger: test-robottelo
pytest: tests/foreman/ui/test_errata.py::test_positive_host_content_library
airgun: 1374

[Satellite-QE]

trigger: test-robottelo
pytest: tests/foreman/ui/test_errata.py::test_positive_host_content_library
airgun: 1374

[Satellite-QE]

PRT Result

Build Number: 6762
Build Status: SUCCESS
PRT Comment: pytest tests/foreman/ui/test_errata.py::test_positive_host_content_library --external-logging
Test Result : ================= 2 passed, 83 warnings in 1183.34s (0:19:43) ==================

[damoore044]

trigger: test-robottelo
pytest: tests/foreman/ui/test_errata.py::test_positive_host_content_library
airgun: 1375