Do not raise ErrorKey on ModelView fields_view_get. Ignore missing fields.
While changing the test_view (issue 9362) I realized that get_view_fields was raising an ErrorKey exception on Fields not found.
The test_view fails if a field does not exists even if the field_view_get ignores the none existing field.
It is my understanding that get_view_fields should simply ignore the fields that not exist and not raise the exception (ErrorKey). Ignore the fields that don't exist.