* refactor: return response with data from ajax
Because we still need to manipulate the data coming back from the server
(files -> challengeFiles) and we want to keep ajax.ts as the interface
between client and server we need to return the manipulated data with
the response.
* feat: re-enable failed updates flushing
* test: failed updates get resubmitted and flushed
* fix: convert settings requests to use { data }
* refactor: use preserveSession
f0f44ca315