Add basic multi-query support to MRVA results view header

[charisk]

Adds a very minimal solution to showing query information for a multi-query MRVA in the results view. This is something we'll expand on in the future.

Checklist

N/A:

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.

[robertbrignull]

Works for me. One small optional comment.

As said earlier, I think merging this now is a good idea so we improve the UI a little bit, and it doesn't block us doing more later.