Fixes ScreenSpaceEventHandler.getInputAction JSDoc

[sanjeetsuhag]

Fixes #8929.

Added a @returns section to JSDoc for getInputType.

[cesium-concierge]

Thanks for the pull request @sanjeetsuhag!

• ✔️ 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]

Thanks @sanjeetsuhag! This doesn't actually fix #8945, since the actual event objects are still not typed, but it looks like it does fix #8929.

One CI passes I'll take a quick look and most likely merge.

[sanjeetsuhag]

@mramato Thanks! Updated the description.

[mramato]

Thanks again.