drive: backend query command

[john-paulsmith]

What is the purpose of this change?

This command executes a list query in Google Drive’s native query language and returns id, name pairs for any matches. It’s useful for locating files quickly in folders with a large number of files, where rclone’s normal list command is slow due to client-side filtering.

Was the change discussed in an issue or in the forum before?

No

Checklist

• [x] I have read the contribution guidelines.
• [x] I have added tests for all changes in this PR if appropriate.
• [x] I have added documentation for the changes if appropriate.
• [x] All commit messages are in house style.
• [x] I'm done, this Pull Request is ready for review :-)

[john-paulsmith]

Thanks very much for your review. I've pushed another commit incorporating these changes.