RetrieveFeatureWorkerVersion endpoint

https://redmine.teklia.com/issues/7497

The frontend will soon need a way to access the details of a worker version that provides an ArkindexFeature without knowing its ID. A new RetrieveFeatureWorkerVersion endpoint should allow this, at /api/v1/workers/versions/feature/{feature}/, where feature is a value in the ArkindexFeature enum.

It must have the same permission requirements as RetrieveWorkerVersion and returns the same response as RetrieveWorkerVersion. Only that instead of retrieving by ID, it calls WorkerVersion.objects.get_by_feature(feature). If there is no worker version providing a feature, it should return HTTP 404.

The OpenAPI documentation can be updated to document that feature specifically takes the values of ArkindexFeature; this won't be automatically guessed because the Django path parameters will not support an enum. Look for OpenApiParameter.PATH in the existing code for examples.