[U] Get only surface nodes.

Sort the merged nodes lexicographically to obtain the surface nodes.
[U] Keep the point names.

Keep the point names deploying PointWithID and name search.
[GL] Using std::lib functions.
[GL] Remove unused var cnt.
[U] md to CMakeLists.txt changes.
[U] Give some progress information.
[U] Better names for readability.
[U] Reworked mesh node search algorithm.

Use the surface mesh instead of the subsurface mesh to find mesh nodes at the top.