Include Vulnerabilities in Global Search results
### Problem to solve
Now that vulnerabilities are "first class" objects inside GitLab, they are persistent for each Project where vulnerability scanning is taking place. Vulnerabilities are not currently searchable via Global Search, making it more difficult to locate a specific vulnerability record or related vulnerabilities across projects or groups.
### Intended users
* [Cameron (Compliance Manager)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#cameron-compliance-manager)
* [Sam (Security Analyst)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#sam-security-analyst)
### User experience goal
Vulnerability records matching the global search query should appear alongside other searched objects (see mockup). Use the vulnerability `name` and `description` fields to populate the displayed search result text. The behavior should also be the same in that I can click on the vulnerability title or ID and be taken to the proper vulnerability record.
### Proposal

### Further details
Ideally, we can also include any `identifiers` for each vulnerability. That way, the user can see, for example, CWE or CVE information from this view as these are likely candidate search expressions. At a minimum, the `identifiers` information must all be searchable as a primary use case is using these to find all instance-wide occurrences of a vulnerability. For example, I might search for `CWE-85` or `CVE-2021-1234`.
### Permissions and Security
Vulnerability objects are only available to gitlab~3207279 customers so the proposed section/tab in the results should not appear to lower product licenses.
Any vulnerability results returned and displayed must match the user's permissions to those vulnerability records. If a user would not be able to view a vulnerability record, no result showing that vulnerability's information should be included nor should the result count include such records.
### Documentation
<!-- See the Feature Change Documentation Workflow https://docs.gitlab.com/ee/development/documentation/workflow.html#for-a-product-change
* Add all known Documentation Requirements in this section. See https://docs.gitlab.com/ee/development/documentation/feature-change-workflow.html#documentation-requirements
* If this feature requires changing permissions, update the permissions document. See https://docs.gitlab.com/ee/user/permissions.html -->
### Availability & Testing
<!-- This section needs to be retained and filled in during the workflow planning breakdown phase of this feature proposal, if not earlier.
What risks does this change pose to our availability? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing?
Please list the test areas (unit, integration and end-to-end) that needs to be added or updated to ensure that this feature will work as intended. Please use the list below as guidance.
* Unit test changes
* Integration test changes
* End-to-end test change
See the test engineering planning process and reach out to your counterpart Software Engineer in Test for assistance: https://about.gitlab.com/handbook/engineering/quality/test-engineering/#test-planning -->
### What does success look like, and how can we measure that?
<!-- Define both the success metrics and acceptance criteria. Note that success metrics indicate the desired business outcomes, while acceptance criteria indicate when the solution is working correctly. If there is no way to measure success, link to an issue that will implement a way to measure this. -->
### What is the type of buyer?
<!-- What is the buyer persona for this feature? See https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/buyer-persona/
In which enterprise tier should this feature go? See https://about.gitlab.com/handbook/product/pricing/#four-tiers -->
### Is this a cross-stage feature?
<!-- Communicate if this change will affect multiple Stage Groups or product areas. We recommend always start with the assumption that a feature request will have an impact into another Group. Loop in the most relevant PM and Product Designer from that Group to provide strategic support to help align the Group's broader plan and vision, as well as to avoid UX and technical debt. https://about.gitlab.com/handbook/product/#cross-stage-features -->
### Links / references
<!-- Label reminders - you should have one of each of the following labels if you can find the correct ones!
Type - for example gitlab~10230929 gitlab~2278648 gitlab~2278655 gitlab~4107678 /label gitlab~15119512 gitlab~15119514 gitlab~15126258 gitlab~15119517 gitlab~15119519 per https://docs.gitlab.com/ee/development/contributing/issue_workflow.html#type-labels
DevOps stage - for example gitlab~4116714
Group - for example gitlab~10690742
Category - for example gitlab~6703392
<!-- Label reminders - you should have one of each of the following labels if you can figure out the correct ones! -->
epic