Remove redundant fields from courseware API. These are all found in courseHome:
- number
- org
- originalUserIsStaff
- isStaff
- verifiedMode
- isMasquerading (virtual field from isStaff and originalUserIsStaff)
Courseware and courseHome both provide tabs to the mfe.
This PR unifies the calls so that tab descriptions are only fetched from courseHome metadata
Remove jest-chain dependencies to make test errors more usable.