Support Vector3d scale for Mesh and ConvexMesh

[RussTedrake]

This has come up a number of times now. For me, it's specifically motivated by #20444. In particular, I've seen a number of mujoco meshes which handle meshes for e.g. the fingers of a two-fingered gripper by using a single mesh and a reflection scale=[-1,1,1].

If the solution goes through in memory mesh files, that's fine for me. If it's better to just teach the proximity engine + renderers + visualizers how to use the Vector3d scale, that's fine for me, too. The immediate victory condition for me would be to

1. have the models in [MuJoCo parser] Support parsing models from mujoco menagerie #20444 currently marked as "error 1" parse correctly,
2. to have them simulate correct contact geometry,
3. to have them appear correctly in at least Meshcat, (e.g. with normals and textures)
4. to have them appear correctly in the default renderer.

If handling permutations of {-1,1} or permutations of {-x,x} is an easier partial resolution of the feature (perhaps it simplifies normals/texture coordinates?), and we throw on other cases, I would be ok with that. It would already cover my current need.

#22024 was a quick attempt, but it would have only helped for the 1 & 2, not 3 & 4.