Add test for props and state melding, and improve implementation

[js-jslog]

https://github.com/js-jslog/harpguru/blob/0bbad2f1aa94c781aac187e256236a698d4790be/src/HarpFace/HoleInteraction/components/index.tsx#L20

The above line solved the problem that during the call to HoleInteraction following props changes, the useState function call setting a degreeId as the initial state is not equivalent to calling setValueToDisplay so the component doesn't appear to rerender.

I need to find a way to test this and a way to solve the problem properly. I don't think the documented use of useEffect is for this purpose.