TNL-328 Cohort/server display auto

[TNL-180](https://openedx.atlassian.net/browse/TNL-180)

I'm not sold on moving the discussion directory within LMS. I would like there to be discussion tests that cover both Studio and LMS interactions with discussions. I'm not very happy with how the tests have ended up in the past (for instance, context experiments-- there are some tests inside LMS, some inside Studio, and some of the Studio ones also bring up LMS). We should consider having tests be about the feature, not Studio or LMS.