Rollback Mesh-based shapes on containing a "const" TriMesh and add documentation

The MeshShape/SurfaceMeshShape will be used for passing DeformableRepresentation from Physics to Collision as well,
so they will have their internal TriMesh updated/changed.

We have 2 case scenario and the documentation specify this difference:
* Rigid => mesh never changes => geometric properties always valid.
* Deformable => mesh changes => geometric properties invalid but the physics does not need them in the deformable case.
Rollback 'const' changes to TriangleMesh/TriangleMeshTriangleMeshDcdContact