0027180: Visualization - improve selection logic of MeshVS_Mesh

0027180: Visualization - improve selection logic of MeshVS_Mesh

MeshVS_Mesh selection logic in MeshVS_SMF_Mesh mode (entire mesh) has been optimized.
MeshVS_Mesh::ComputeSelection() now creates single sensitive entity
MeshVS_CommonSensitiveEntity (new class) instead of small sensitive entity on each element.
MeshVS_SensitiveQuad (new class) and Select3D_SensitiveTriangle are used instead of Select3D_SensitiveFace for local selection to reduce memory consumption when possible.