Use known translation if exists to get groupname

@singingwolfboy fixes the one question I found in the release. Do you think you can merge this into rc while I write a unit test before I ask for merge into master? The bug was that if the org or run has a period, my code which tries to figure out how to query the permissioning system gets it wrong.

Another approach which will be slower but more robust would be at line 41 to generate every possible parsing of location as old location course_id (put the / pairs in each period loc); however, I believe the only way a user could get the dotted url is via the accessor which ensures there's a mapping before giving the url.