Added ID to content model.

src/Squidex.Domain.Apps.Entities/Contents/Edm/EdmModelBuilder.cs

@@ -54,6 +54,7 @@ namespace Squidex.Domain.Apps.Entities.Contents.Edm
             });
 
             var entityType = new EdmEntityType("Squidex", schema.Name);
+            entityType.AddStructuralProperty(nameof(IContentEntity.Id).ToCamelCase(), EdmPrimitiveTypeKind.String);
             entityType.AddStructuralProperty(nameof(IContentEntity.Created).ToCamelCase(), EdmPrimitiveTypeKind.DateTimeOffset);
             entityType.AddStructuralProperty(nameof(IContentEntity.CreatedBy).ToCamelCase(), EdmPrimitiveTypeKind.String);
             entityType.AddStructuralProperty(nameof(IContentEntity.LastModified).ToCamelCase(), EdmPrimitiveTypeKind.DateTimeOffset);