DEV: Add vbulletin5 bulk importer (PR #12904)

This is a pretty straightforward bulk importer, just tailored to the vBulletin 5 database structure.

Also made a few minor improvements to the base importer – should be self explanatory in the code.

GitHub

Was that n intended?

Nitpick, but you could LIMIT 1 since you’re interested in only 1 result

It likely was. For this DB the n didn’t exist in the quotes. I’ll revert the change.

It’s worth leaving as a note – I don’t have a great way to test the change at this time.