Extend integration test workflow to be able to run on frozen and candidate releases

[jcfreeman2]

This is Issue is motivated by some hiccups trying to run the minimal system quick test on this morning's candidate fddaq-v5.2.1-rc1-a9 release. It seems like it would be a good idea if we extended the integration test workflow to allow users to manually pass it the name of an arbitrary frozen or candidate release to run on (this is already available for nightlies). It would of course require adding some if-then logic to account for the fact that dbt-setup-workarea uses different arguments based on the kind of release, but shouldn't be too difficult.