fix feature.setProperty() to create a new property if it doesn't already exist

[ptrgags]

Fixes #10773

This fixes the regression in setProperty() for unknown propertyId by:

• Updating JsonMetadataTable to create a property if it doesn't exist
• Updating PropertyTable to create a JsonMetadataTable if it doesn't exist, then using this._jsonMetadataTable.setProperty() to create the new property if it doesn't exist.

Other notes:

• I updated the precedence order to put the JSON properties after the batch table hierarchy for consistency. Interestingly, the old Cesium3DTileBatchTable is inconsistent between getProperty and setProperty.

Sandcastle example -- the property will now be created at runtime, so the console will log This is a new property several times, instead of undefined like it does on main.

[cesium-concierge]

Thanks for the pull request @ptrgags!

• ✔️ 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.

Reviewers, don't forget to make sure that:

• Cesium Viewer works.
• Works in 2D/CV.

[ptrgags]

This is now ready for review. @sanjeetsuhag could you review when you get a chance?

[sanjeetsuhag]

Changes look good. Tested it with different tilesets and it seems to be the right fix. Thanks @ptrgags!

[sanjeetsuhag]

@ptrgags Could you add an entry for CHANGES.md?

[ptrgags]

@sanjeetsuhag my bad, I had updated the changelog locally but forgot to push 😅. Pushed it just now!