Fixed few more UI tests

- Fixed following repo tests:
  - `test_remove_repo` : updated locator for remove repository button
  - `test_positive_update_1` added wait_for_ajax()
- Fixed compute resource, media tests.. updated data for these tests
- Blocked sync plan tests and a architecture test with bz ID


I think `self.wait_for_ajax` could be called at the end of `repository.search` method. Inheriting Base here does not make much sense because the purpose of a TestCase instance and the Base class are different.