Implement the first UI test included in the current RHTAP E2E test pipeline.

The UI test should run only when the specific label is set to a pipeline.

GitLab authorization implementation should be easier than the GitHub one, so I suggest starting with GitLab auth.

The test should run after the "common" E2E test ends and should check the already created component. It should check all the tabs that are affected by RHTAP-specific plugins. The test should not perform any complex actions such as triggering a new pipeline etc.