Autoselect xColumn and yColumn

The major ask is that the HistogramPlot and ScatterPlot render properly when viewProperties.xColumn or viewProperties.yColumn is null. The functionality to automatically fill these is currently held in a selector somewhere, which obfuscates the relationship between the view properties being generated by the createView function and the requirements of these components.

Start by tracing createView, the selector that currently fills viewProperties.xColumn and yColumn, and the HistogramPlot and ScatterPlot components. Verify how each component behaves when either property is null; done means both plots render properly without relying on hidden selector behavior.

Written by the indexing model from the issue text.