mooclet backend: send "rewards" on /log

[danoswaltCL]

Dependent on #1934

When users log "reward" metrics, we will trigger a lookup for experiment and user condition enrollment, and proxy a call to post the reward to the Mooclet server.

For reference:
(https://github.com/CarnegieLearningWeb/UpGrade/tree/demo-branch).

https://carnegielearning.slack.com/archives/C08A2LSPM5J/p1738243122240099 for demo and diagrams.

Requirements:

If client /log's a metric that matched to a rewardMetricKey property in MoocletExperimentRef table, this will trigger a call to send the "reward" value to the Mooclet server.

The data needed for sending the reward value to the Mooclet API is:

• moocletId
• outcomeVariableName
• versionId
• value (i.e reward, will be 1 or 0)

So I think we will need to:

• Find MoocletExperimentRef by rewardMetricKey

If found, get the versionId:

• Find user's condition in IndividualEnrollment using user id and experiment id.
• Find the version id by matching the condition id to the corresponding "version" in MoocletExperimentRef.versionConditionMaps

Determine value (reward)

• The rewardMetricKey will always either give SUCCESS or FAILURE.
• Success = 1, Failure = 0

Get outcomeVariableName from MoocletExperimentRef (we should add this property to the MoocletExperimentRef as a column and add it on experiment creation instead of searching in the policyParameters for it here).

POST these details to /value:

{
  moocletId,
  outcomeVariableName,
  versionId,
  value
}