22830: EDF 9557 SMESH: Quadratic conversion of a mesh fails

22830: EDF 9557 SMESH: Quadratic conversion of a mesh fails

In SMESH_MeshEditor copy node positions in Duplicate*()
In SMESH_MesherHelper
- cache face tolerance
- in GetNodeUV() prevent SIGSEGV if a node is on EDGE not belonging to a FACE
- in GetNodeUV() check if a VERTEX is a seam in a given FACE, not in another
- avoid returning myShape from GetMediumPos() when it can be wrong

52592: Invalid values of Length 2D control

- avoid using not initialized values for showing control values of a group