If roles exist when a collab's roles are submitted, delete any roles not in the submission

[eberleant]

Tasks

• Delete roles not in the submission
• Make role submission transactional
• Re-evaluate error handling & error conditions
• Re-evaluate which controller role submission should be in (collab vs. role controller)
• Figure out if there's a better way to handle role submission that uses the relationship between people, collabs, and roles?

Related

• Blocks When a collab is entered that already has data/roles, display them youtaite-network-client#51