Resolve "Unable to close performance bar"

What does this MR do?

Move performance bar above the .modal element that is added to body.

Clicking the trigger for gl-modal possibly triggers bootstrap modal background.

Underlying issue is duplicate modal backdrops being added, but that can be fixed separately.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides

Closes #50552 (closed)