Add distinct color for interactable observations in the `OrbitalSim`

There is some [logic in the `Observation` component](https://github.com/lsst-epo/epo-react-lib/blob/develop/packages/epo-widget-lib/src/widgets/OrbitalSim/Observation.jsx#L13-L21) that determines what color to apply to which mesh.

A field (`isInteractable`) on the orbital data can be used to determine if the `observation` is interactable or not. I think if they _are_ interactable we can make them a light yellow.

Once you have this working in your local environment, share a screenshot in the investigations channel to get feedback before merging.