Covering 100% of enterprise features with integration and end-to-end tests
### Background
We need to ensure that all Enterprise features are covered with integration tests coverage. We do have tests for EE features they should have stronger visibility in test results or in every deployment.
An effective iteration would be to make sure that all enterprise features are covered with smoke and regression tests.
The tests under `https://gitlab.com/gitlab-org/gitlab-ee/tree/master/qa/qa/specs/features/ee`
### Proposal
* Do an audit of integration and end-to-end tests for all of our enterprise features. https://gitlab.com/gitlab-org/quality/team-tasks/issues/189
* Start off with `Dev` first then work our way into other areas (do this while accounting for staffing, we do not have a full team in other areas as Test Automation Engineer coverage is spread thin)
* Identify any gaps that need to be filled. Criteria: if the functionality is broken it is equivalent to an ~S1 or ~S2 bug filed by a customer.
* Once identified, create test case issues in https://gitlab.com/gitlab-org/quality/testcases marked with `~enterprise` or `~ee`
* Fan out effort in closing out the gaps, while in parallel work on improving the visibility of these tests in our nightly, staging and deployment runs.
* Dedicated slack reporting.
* Dedicated HTML report.
* Ensure that the delivery team runs this enterprise features test suite in every deployment along with our smoke tests.
* We would like to move to having this test suite gate the deployments eventually.
### Tasks
* [x] Audit end-to-end tests for all enterprise features
* [x] Identify testing gaps in end-to-end test coverage for enterprise features
* [ ] Add tests to close testing gaps for Starter tier features
* [ ] Add tests to close testing gaps for Premium tier features
* [ ] Add tests to close testing gaps for Ultimate tier features
* [ ] Ensure that the delivery team runs this enterprise feature test suite in every deployment along with smoke tests
epic