Support loading meshes in glTF format

[mahiuchun]

glTF 2.0 is a new standard 3D mesh format that supports PBR natively.

Desired behavior

MeshManager::Load() be able to load glTF 2.0 mesh files with file extensions .glb and .gltf.

Alternatives considered

N/A

Implementation suggestion

We can use https://github.com/syoyo/tinygltf to parse glTF files.

Additional context

https://www.khronos.org/gltf/

[guyVaarst]

I am a bit confused - this ticket implies that gazebo doesnt yet support gltf, but https://gazebosim.org/docs/all/release-features implies it does. Does Gazebo support glTF?

[azeey]

Yes, glTF support was added in #393. I'll close this issue.