Throw an error if an invalid body is used in a REST call

Steps to reproduce

1. Create a File document and populate the files:files metadata with some items
2. Make the following REST call to update the newly created document - change the id in the URL

   HTTP PUT http://localhost:8080/nuxeo/api/v1/id/6733ed51-e6fa-4b37-9b8d-9f10413b5da9
   
   {
       "entity-type": "document",
       "type": "File",
       "properties": {
           "dc:subjects": [
               "art/architecture"
           ]
       }
   }
   

3. observe, in the UI or in the REST response, that the files:files metadata is now empty

The problem is due to an incorrect JSON body, where the uid is missing.

However an incorrect body should raise an error, not provoke a data loss

Expected behavior: return an error to inform the user that the request is invalid (JSON body invalid)