Added a multi files test using the test data of the multi files test as provided by Jeremey.Is also part of review for Issue [MWDAM-1666]Related to Issue [MWDAM-1673]
Refactored: move method SurfaceLine.CreateLoweredSurfaceLineForGivenLayerThickness() to a new class and method SurfacelineProcessor.CreateLoweredSurfaceLine()Related to Issue [MWDAM-1658]
Cleaned code a bit, improved test for offset Issue [MWDAM-1659], added error message for console at end of execution when errors are found.Related to Issue [MWDAM-1659MWDAM-1661]
Cleaned code a bit, added test for offset Issue [MWDAM-1659], improved generation step 2 by making sure the offset = 0 for that step.Related to Issue [MWDAM-1661]