Fix missing pipeline test report bug

What does this MR do?

Related to #301236 (closed)

This is for the test report that is found on the pipeline page.

When classname or name is null in a test case, then the test view fails to load. This was working before, but one of the gitlab-ui components we use (friendly-wrap was recently updated and now breaks when passing in a null value.

This fix just defaults the value of those properties to an empty string if those properties are null.

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