add calcPolygon()
rename TwoDVolumeIntegratorCore to QuadranglePolygonVolumeIntegratorCore
clear redundant code of calcArea()
add SymmetricTriangleQuadratureSupport and tests
add getter of vertesCoords
add TrianglePolygonVolumeIntegratorCore
add TriQuadVolumeIntegratorCore and make it default in tests