Add a retry to Group security dashboard

What does this MR do?

The Group security dashboard test was intermittently failing.

It was found that if this test was ran first, or in isolation, there was a delay between the initial creation and populating of the project to the Group level security dashboard being populated.

(If other tests in the spec were ran first, this allowed time for the dashboard to be populated, which was why it was intermittent)

This MR adds a retry to check if the dashboard has been populated, refresh if not.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team