Mutually exclusive FOs
Closes #361 (closed)
Changes backend:
- New feedback property denoting whether the children of a given option are exclusive or not.
- changed PUT by PATCH in feedback api
- Whenever the exclusivity changes, it goes through all solutions and marks as ungraded those with invalid feedback.
- Whenever a FO is selected and the parent is exclusive, it removes any other selected sibling and children of it and marks the requested option.
Changes frontend:
- Switch in feedback block edit that modifies the exclusivity property of the parent.
- Squared vs. round tags are used to distinguish non-exclusive vs. exclusive options.
- Invalid feedback can't be approved and is marked in red.
Edited by Anton Akhmerov