Add case_id as a standard column for any form user configurable report.

@czue @nickpell 

I took a stab at this, wanted it for a discussion with Tableau people tomorrow evening.  This doesn't address apps that don't have case sharing enabled, because I think if a field doesn't exist, it will just be blank in the postgres table.  Would definitely be cleaner to avoid adding the indicator if case sharing isn't enabled.

i think we only want to add this if the form has case management configured. also this won't work in advanced app builder or with parent cases, but that's probably ok for the first pass