Rename ModelExperimental files that don't conflict with Model

[j9liu]

This PR renames several ModelExperimental files that don't have Model counterparts:

• ModelExperimental3DTileContent
• ModelExperimentalAnimationChannel
• ModelExperimentalArticulation
• ModelExperimentalArticulationStage
• ModelExperimentalDrawCommand
• ModelExperimentalRuntimeNode
• ModelExperimentalRuntimePrimitive
• ModelExperimentalSceneGraph
• ModelExperimentalSkin
• ModelExperimentalStatistics
• ModelExperimentalType

For all of these files, the "Experimental" part of the file / class name has been removed.

[cesium-concierge]

Thanks for the pull request @j9liu!

• ✔️ Signed CLA found.

Reviewers, don't forget to make sure that:

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

[j9liu]

@ptrgags could you review when you get the chance?

[j9liu]

Found a bug while I was testing (though it's happening on main too):

In the 3D Tiles Next CDB Yemen Sandcastle:

• Select style buildings based on height
• Switch to the Airport view
• Move the camera around the area. Eventually this error will pop up:

This is the stack trace:

"Original stack:
Original stack:
Original stack:
Error
    at new DeveloperError (http://localhost:8080/Build/CesiumUnminified/index.js:11257:11)
    at Check.typeOf.number.greaterThan (http://localhost:8080/Build/CesiumUnminified/index.js:11324:11)
    at new MetadataTable (http://localhost:8080/Build/CesiumUnminified/index.js:87532:31)
    at parseFeatureMetadataLegacy (http://localhost:8080/Build/CesiumUnminified/index.js:105204:29)
    at http://localhost:8080/Build/CesiumUnminified/index.js:105350:34
    at async Promise.all (index 0)
Handler stack:
Error
    at new RuntimeError (http://localhost:8080/Build/CesiumUnminified/index.js:13876:11)
    at ResourceLoader.getError (http://localhost:8080/Build/CesiumUnminified/index.js:87690:24)
    at http://localhost:8080/Build/CesiumUnminified/index.js:105366:32
    at async Promise.all (index 0)
Handler stack:
Error
    at new RuntimeError (http://localhost:8080/Build/CesiumUnminified/index.js:13876:11)
    at ResourceLoader.getError (http://localhost:8080/Build/CesiumUnminified/index.js:87690:24)
    at handleError6 (http://localhost:8080/Build/CesiumUnminified/index.js:106215:22)
    at http://localhost:8080/Build/CesiumUnminified/index.js:106201:12
Handler stack:
Error
    at new RuntimeError (http://localhost:8080/Build/CesiumUnminified/index.js:13876:11)
    at http://localhost:8080/Build/CesiumUnminified/index.js:108229:26"

[lilleyse]

Possibly related to CesiumGS/cdb-to-3dtiles#69?

N12E045_D300_S001_T001_L6_U52_R1.glb has no meshes

[ptrgags]

The renaming looks good, and I searched through the code to make sure nothing was missing.

Thanks @j9liu!