Atomize the metrics models and APIs
https://redmine.teklia.com/issues/2483#change-55343
- Remove the
MetricKey
andMetricValue
models - Move the
MetricMode
enum to thetraining.0001
migration - Remove the
CreateMetricValue
andCreateMetricValues
endpoints
You may need to update the test fixtures since they include some Django permissions, even though we don't use those.