Functional node normalizer tests are now higher priority

[jh111]

Now that both the test harness and the product are relying on node normalizer, it is important to run some node normalizer tests to make sure it doesn't break and go unnoticed.

It's unlikely to break, but could be very bad if it does. I recommend a short set of tests. Perspective to consider include:

• functional features
• node sources
• node metadata
• equivalence classes
• error handling