Fix direction of normals of TrapezoidVolumeBound surfaces.
Fix the direction of the alpha and beta boundary surfaces of TrapezoidVolumeBound. Also check normals in unit test.
This is an update of MR!74612 which fixed the position of the boundary surfaces but the surface normals of the alpha and beta boundary surfaces were pointing inwards. This is corrected by this MR. Now all boundary surfaces point outwards.
Also extended the test to check the normal direction.