* Update Financial Assistance logic
Use the zendesk proxy app instead of the unsupported zendesk library.
* Move to pre-fetching the group IDs.
Rather than making extra requests to zendesk to list all groups and find
a specific group ID. Just make a pre-filled list of group IDs for the
groups we care about. When a group name is passed in, it is checked
against this list and the ticket is created in the correct group so the
right people can respond to it.
This change creates a new lms/cms endpoint which accepts unauthenticated
requests to securely create zendesk tickets. This allows javascript code to
create tickets without exposing ZENDESK_OAUTH_ACCESS_TOKEN
EDUCATOR-1889
