OpenVolumeMesh ⇄ Geogram mesh conversion

The initial goal was to extract a piece of code from an archived repo whose submodules are obsolete.

The ultimate goal is to subclass MeshIOHandler in Geogram.

Limitations

Mesh attributes are not handled.

↓Input \ Output→	.ovm	.mesh/.meshb/.geogram
.ovm	N/A	❌
.mesh/.meshb/.geogram	🚧 WIP	N/A

↓Input \ Output→	.ovm	.mesh/.meshb/.geogram
.ovm	N/A	✅
.mesh/.meshb/.geogram	❌	N/A

./configure
cd build/<platform>
make

./ovm.io path/to/input/mesh path/to/output/mesh