FAL-1509 convert roles and skills to many-to-many
This allows courses to have 0 or more roles and skills associated. Previously it was 0 or 1.
Test instructions:
- install this in a koa devstack and run migrations
- ensure courses are indexed
- navigate to the lms admin, and the course search group
- add some roles and skills to courses
- start up https://gitlab.com/opencraft/dev/frontend-app-course-search - use the revision from frontend-app-course-search!4 (merged)
- run some searches and verify:
- expected courses returned in results
- expected number of roles/skills in dropdown selects (it should show a number to indicate how many courses would be returned on selecting that role/skill)
Reviewers:
Edited by Raul Gallegos