Refactor and fix of some Errata UI tests

[LadislavVasina1]

Problem Statement

I have fixed some failing Errata UI tests. Tests were mainly failing because they were trying to test the old, no longer-used content_host page and used old fixtures.

Solution

After a discussion with @vsedmik I have rewritten the test that I have fixed so they test the similar/same thing on the new host page on Content-Errata Tab. To reflect the changes made in test I have renamed the test in the following way

• test_positive_content_host_library -> test_positive_check_errata
• test_positive_content_host_search_type -> test_positive_errata_search_type
• test_positive_show_count_on_content_host_details_page -> test_positive_check_errata_counts_by_type_on_host_details_page

Needs https://github.com/SatelliteQE/airgun/pull/1337