ImageryLayer readonly imageryProvider prop

[TheMrCam]

Overview

The Resium docs and Cesium docs agree that ImageryLayer#imageryProvider is a readonly property. It appears that Resium does not accurately respect that, and as a result the ImageryLayer isn't being recreated on prop change.

Is this an issue?

I primarily wanted to make this issue to ask permission to create a small PR that remedies the problem by moving 'imageryProvider' from otherProps to cesiumReadonlyProps, as I already have and use this as a custom Resium component downstream.

However, there's entirely a chance that I'm actually missing something or doing something slightly incorrectly, in which case I wouldn't want to introduce any changes to Resium that would affect other developers.