Improve data audit + organize job folder

[nm3224]

changes & context

• putting in guard rails for gateway courses <=200 to not auto populate config - instead check with school and manually add to config
• trying to save out logs for all steps (including for inference)
• refactoring log saving code so it's less redundant
• created a training and an inference folder under the job/run id for organization
• adds cohort/term breakdown for checkpoint logic
• shows what subsets of checkpoint df, selected students df and target df end up in final dataset
• added missing grade feature to feature table

[nm3224]

@vishpillai123 this is good to merge now!

[vishpillai123]

Ok we're almost there Noreen! Great work so far on the gateway courses implementation & the logging. I also just looked at one of the schools you ran recently, and the logs look perfect!!! Nice job.

Just wanted to see if the model prep changes were needed now, or if we can wait till later, especially if we haven't tested the changes yet.