Free typed arrays for instanced models

[j9liu]

Closes #10421. This addresses the temporary buffers created by InstancingPipelineStage. The attributes are loaded as typed arrays for reasons like computing transform matrices, or computing the min/max of the translation attribute if it's not provided. But afterwards, there is no further manipulation of the data, and thus no reason to keep recreating the buffers from those typed arrays.

This PR rewrites parts of I3dmLoader and GltfLoader to load in transform attributes as typed arrays only if the rotation attribute is defined (i.e. matrices have to be computed). Additionally, feature IDs were for some reason being loaded as typed arrays, so they have been restricted to loading as buffers instead.

TODO: need to profile the changes for i3dms in combination with other functions (those that require rebuilding draw commands)

[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.

Reviewers, don't forget to make sure that:

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

[j9liu]

Did some performance testing. Here's the difference between heap screenshots, using this Sandcastle:

before changes (main)	after changes
57 array buffers	46 array buffers

For runtime performance, I used this Sandcastle, which toggles the lightColor of the tileset. This forces the models to rebuildDrawCommands, so hopefully the difference as a result of changing InstancingPipelineStage would be noticeable. I recorded for 11 seconds, toggling the button 10 times within that timeframe, and got these results:

before changes (main)	after changes

Overall, I believe this PR improved both memory usage and runtime performance. It's now ready for review @ptrgags

[ptrgags]

@j9liu looks good, I can reproduce your profiling results. Just a couple comments

[j9liu]

@ptrgags updated!

[ptrgags]

Updates look good, thanks @j9liu!