[Idea] Add Gmsh (.msh) support to Stream_support

[codepk37]

Hi,
I have been working on adding Gmsh support to CGAL’s Stream_support and wanted to get some feedback.

So far I have:

1. ASCII Gmsh v2 reader (nodes/elements, boundary extraction from tetra meshes, polygon-soup orientation).
2. Small demo viewer

Code is here: https://github.com/codepk37/cgal

For GSoC, I’m thinking of keeping the 90h scope focused on:

• refining the prototype and integrating it into Stream_support
• adding tests and examples
• handling non-manifold cases

If needed, I can extend it to support parts of v4 and basic binary detection.

Does this direction make sense for CGAL?
Any suggestions on how this should fit into the existing IO design would be really helpful.

Thanks!