Run queries in folders on an old database opens many upgrade dialogs

[johnlugton]

Describe the bug
When using "Run queries in selected files" on a CodeQL db that needs an upgrade you get the dialog once per query.

To Reproduce
Try to run multiple queries at once on an outdated CodeQL db

Expected behavior
One upgrade prompt between all queries

[aeisenberg]

Thanks for reporting this bug. Our multi-run query operation is too simplistic. We're simply invoking the run command once for each selection, which allows for this bug as well as #464.