Add test that triggers #5685

The irrelevantPropertiesBeforeQuery test is passing but
irrelevantPropertiesAfterQuery is not. Both tests should pass because
the order of properties in the JSON input shouldn't mattter.
Detect unsupported fields after supported field

Fixes #5685

The validate API was failing to reject JSON input that had unsupported
fields placed after a supported field. This was causing invalid requests
to be reported as valid.