Improve JSDoc/TypeScript support for Material properties

[mramato]

All of the MaterialProperty constructors take primitive types in addition to Property instances (and automatically wrap the primitive type in a ConstantProperty). The JSDoc was incorrect on this leading to sub-par TS type definitions. Also fixed a missing optional result parameter in the JSDoc for EllipsoidGeodesic.interpolateUsingSurfaceDistance.

Fixes #8898

[cesium-concierge]

Thanks for the pull request @mramato!

• ✔️ Signed CLA found.
• ❔ CHANGES.md was not updated.
  • If this change updates the public API in any way, please add a bullet point to CHANGES.md.
• ❔ Unit tests were not updated.
  • Make sure you've updated tests to reflect your changes, added tests for any new code, and ran the code coverage tool.

Reviewers, don't forget to make sure that:

• Cesium Viewer works.
• Works in 2D/CV.
• Works (or fails gracefully) in IE11.

[mramato]

I'm looking at way to bootstrap some basic TypeScript tests so that we can avoid regressions.

[mramato]

For those new to reviewing TS related PRs, in 99% of the time (like this one) it's literally just fixing JSDoc.

[mramato]

I pushed one more small change to fix the individual properties to be @type {Property|undefined}, since they were not marked that way. Unless there's more feedback, this is ready.