Included content Length (coscine/issues#1335)

src/Blob/Controllers/BlobController.cs

@@ -223,6 +223,7 @@ namespace Coscine.Api.Blob.Controllers
             try
             {
                 var resourceTypeOptions = _resourceModel.GetResourceTypeOptions(resource.Id);
+                resourceTypeOptions.Add("ContentLength", Request.ContentLength.ToString());
                 var resourceTypeDefinition = ResourceTypeFactory.CreateResourceTypeObject(resource.Type.DisplayName, _configuration);
                 if (resourceTypeDefinition == null)
                 {