Build endpoint UpdateModelVersion

Depends #962 (closed)

We need a new endpoint named UpdateModelVersion, available in the training API group and exposed as PUT on /api/v1/modelversion/:model_version_id

It must be available to any controbutor or admin of the related model.

These fields are updatable immediately:

• description
• tag
• configuration

If a user updates the state from created to available (only case possible), the backend will check the uploaded payload in the request time:

• checking that the file is present on the backend (through a HEAD operation)
• checking its file size (through HEAD too - no download, the information should be in the file metadata made available by the S3 server)

If the file is available and match the size from the database, set the state to available, otherwise set the state to error and raise a 400