Fix check for style translucency

[j9liu]

Fixes #11300.

This PR corrects the check in Model.applyColorAndShow. The specs didn't catch it because there wasn't a unit test for models without feature tables, so one such unit test was added.

Local sandcastle for testing.

[cesium-concierge]

Thanks for the pull request @j9liu!

• ✔️ 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.

[ggetz]

Awesome, thanks for the fix and the additional unit test @j9liu!

[j9liu]

@ggetz just pushed a commit to fix the changelog!

[ggetz]

Thank you again @j9liu!