Limit amount of JUnit tests returned

What does this MR do?

Currently, we do not cap the number of tests returned to the frontend, thus in some extreme cases, we can see an MBs of data stored in Redis.

This adds an upper limit of 100 tests per-suite, with at least 5 returned for a given classification. We assume that the most important are new failures, next: existing failures, and last resolved failures.

We will continue showing the total counters correctly, but we will limit the number of tests that will be presented.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/64035

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance 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