Support worker run in UpdateWorkerActivity

Depends #1558 (closed)
Refs https://redmine.teklia.com/issues/3383

We'll support a worker run ID provided as the path ID in UpdateWorkerActivity in order to avoid immediate deprecation of the endpoint (and handing yet another migration).

The endpoint would simply try to fetch first an existing WorkerRun with that ID, and fallback to a WorkerVersion.

When a WorkerRun is available, the values of model_version and configuration are used to find and update the targeted WorkerActivity