Cannot export to CSV concept sets attached to a cohort characterization

[ttemnikova]

Expected behavior

Between click on the "Export All Concept Sets To CSV" button and downloading a file, there is a progress bar or loader.
All concept sets are downloaded as a .zip of three .csv files (conceptSetExpression, includedConcepts and mappedConcepts).
The button "Export All Concept Sets To CSV" exists on all tabs with the similar function (e.g. Incidence Rates, Reusables, Feature Analyses) or does not exist everywhere if it is redundant

Actual behavior

GET WebAPI/cohort-characterization/<cohortID>/export/conceptset returns 403 without any other info

Steps to reproduce behavior

1. Login
2. Go to Cohort Characterizations and create a new characterization
3. Go to Concept sets tab
4. Create or import concept set(s)
5. Click the button "Export All Concept Sets To CSV"