featuresDisplayOrder and axis.exclude

## Use Case

The data schema allows for `featuresDisplayOrder` and `xAxis.exclude` and `yAxis.exclude` to control which data features are visible in the axis dropdowns. It appears that the `exclude` options are not yet implemented , and using `featuresDisplayOrder` but leaving out a feature does not successfully hide that feature.

## Solution

Workaround: remove the feature from feature defs json file. this is a global removal and doesn't work in the targeted way that the axis.exclude might work.

Solution is to actually fully implement featuresDisplayOrder allowing missing features (or determine if that should be considered an error), and to fully implement xAxis.exclude and yAxis.exclude behavior.