Add obj mesh support to viewer

[Wumpf]

What

• Fixes Unlike documented, Asset3D doesn't support obj files yet #3653

More like "enable". Works fine, but naturally doesn't support mtl files yet.

⚠️ Let's have a look on the Wasm size tracking for this one before merge ⚠️

Tested using the checked in blender exported obj file https://github.com/rerun-io/rerun/blob/main/crates/re_renderer/examples/rerun.obj.zip, unpacked and then python ./docs/code-examples/asset3d_simple.py crates/re_renderer/examples/rerun.obj

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)
• I have tested demo.rerun.io (if applicable)

• PR Build Summary
• Docs preview
• Examples preview
• Recent benchmark results
• Wasm size tracking

[emilk]

Was there some docs needing updating too, or were they correct?

And yes, good call on checking wasm size before merge

[Wumpf]

only docs I noticed in need of updating is the note I made on lack of mtl support. Btw. on that the file used does specify a mtl file, so ignoring it silently works (should probably do a warning, but whatever, punting on this)

Otherwise, all our docs seem already to claim obj, gltf and glb support!

[Wumpf]

oh shoot. I didn't push that note yet, looks like I'm not very focused today 😳

[Wumpf]

wasm: 15.33 MiB -> 15.37 MiB

That's not nothing, but acceptable for now.