add some validation for ``QuadrilaturalElement`` https://github.com/BriefFiniteElementNet/BriefFiniteElement.Net/blob/master/BriefFiniteElementNet.CustomElements/Elements/QuadrilaturalElement.cs and https://github.com/BriefFiniteElementNet/BriefFiniteElement.Net/blob/master/BriefFiniteElementNet.CustomElements.Test/QuadrilaturalElementTests.cs