Support changing the color of features in a data layer

[laurenwalker]

Users should be able to change the color or color scales of the features in a data layer in Cesium (after MVP)

[robyngit]

This should also include updating the legend dynamically based on colour choices.

[robyngit]

Reminder that when it comes to colour scales, we should provide users a choice of scientifically derived and perceptually uniform gradients, see the article Crameri, F., Shephard, G.E. & Heron, P.J. The misuse of colour in science communication. Nat Commun 11, 5444 (2020).

[robyngit]

If this issue is referring to the ability to configure colors for a layer in a cesium map, it is now ready in the develop branch, with the exception of continuous and classified color palettes. If this issue is instead referring to creating a UI for people to change layer colors while viewing a map, then it is a duplicate of #1798