Colordata

[fredludlow]

This is partly in response to #892, Adds a colorData parameter to representations, that colormakers may make use of, and a new builtin structuredata colormaker will make use of this where colorData is of shape

{ atomData?: { [atomIndex: number]: number}, 
  bondData?: { [bondIndex: number]: number}
}

See the examples color/atom-data and color/bond-data for usage.

I'm open to alternative ways to achieve this. One obvious alternative would be to allow arbitrary (atom-based?) data to be added to Structure objects. The main reason I didn't do this is that I couldn't think of a clean way to connect updates in the extra data to updating coloring of representations without some objects knowing more about others than they ought to. (If Structure sends a signal saying that indicates the data with attribute name "_some_fancy_model_output" has been updated, should a representation trigger a re-color?)

Note that at runtime there's no check that you're passing in colorData of the shape described above, so it could be used to pass any data through to your custom colormaker - if that's preferable as a general method we could update the typing info to support it.

Comments (major changes as well as naming/nitpick etc) very welcome!

[ppillot]

These are minor suggestions.

Maybe a major concern would be about the expected format as using an array should be favored to an inlined object.

[fredludlow]

Thank you very much @ppillot for the review! I think all the issues you raised are fixed in 7505d9e, plus a bug I'd overlooked with how bondColor interacts with the manageColor decorator.

[ppillot]

I'll have a look when I can. Thanks for the hard work @fredludlow!

[ppillot]

Thanks! Great additions, and clear examples.
Tested and approved