Improved node docs

[RunDevelopment]

You might to review this PR with whitespace changes hidden. Prettier went wild in some places.

Changes:

• Improved type printing. false | true will now be bool, and small integer intervals will now be unfolded (e.g. 1 | int(3..4) -> 1 | 3 | 4).
• Added "optional" tag for option inputs and removed null from type.
• Don't show outputs users can't connect to. This only affects the large image output of View Image.
• Don't show auto iterator input in helper nodes.
• Fixed example inputs not being the default inputs.

The last point needs a bit more explanation. The issue was that a number input always retained its previous value if the input id was the same as the in the previously looked-at node. E.g. go to Crop Edges and then to Crop Offsets and Width and Height were set to 0 (which is invalid). This was a bug in NumberInput and I fixed it.

But that wasn't good enough for me. Input still reset to their default values when we show example nodes. This changes the global node state, which really isn't ideal here. So to prevent future bugs, I changed the way groups and SchemaInput (= the abstraction layer on top of input components) set input data. They previously got setNodeInputValue from global node state, but now they get a setInputValue function passed in as a prop. This allows us to control the way inputData is modified. In the case of doc examples, we manage our own inputData state separate from global node state.