BUG: QuadEdgeMeshPoint should be properly initialized by {}

Defaulted the default-constructor of `QuadEdgeMeshPoint`, and added an
initializer to its data member m_Edge, to ensure that an instance of this type
can be properly initialized by an empty initializer list, `{}`.

Aims to fix the dynamic analysis defects reported by Jon Haitz Legarreta Gorroño
at InsightSoftwareConsortium#4884 (comment)

Modules/Core/QuadEdgeMesh/include/itkQuadEdgeMeshPoint.h

@@ -59,7 +59,7 @@ class ITK_TEMPLATE_EXPORT QuadEdgeMeshPoint : public Point<TCoordRep, VPointDime
 #endif
 
 public:
-  QuadEdgeMeshPoint();
+  QuadEdgeMeshPoint() = default;
   QuadEdgeMeshPoint(const Self &) = default;
   QuadEdgeMeshPoint(QuadEdgeMeshPoint &&) = default;
   QuadEdgeMeshPoint &
@@ -118,7 +118,7 @@ class ITK_TEMPLATE_EXPORT QuadEdgeMeshPoint : public Point<TCoordRep, VPointDime
   Initialize();
 
 protected:
-  TQuadEdge * m_Edge; /**< Entry edge for this point into an Onext ring */
+  TQuadEdge * m_Edge{}; /**< Entry edge for this point into an Onext ring */
 };
 } // end namespace itk
 

Modules/Core/QuadEdgeMesh/include/itkQuadEdgeMeshPoint.hxx

@@ -30,12 +30,6 @@ QuadEdgeMeshPoint<TCoordRep, VPointDimension, TQuadEdge>::Initialize()
   m_Edge = static_cast<TQuadEdge *>(nullptr);
 }
 
-// ---------------------------------------------------------------------
-template <typename TCoordRep, unsigned int VPointDimension, typename TQuadEdge>
-QuadEdgeMeshPoint<TCoordRep, VPointDimension, TQuadEdge>::QuadEdgeMeshPoint()
-{
-  this->Initialize();
-}
 
 // ---------------------------------------------------------------------
 template <typename TCoordRep, unsigned int VPointDimension, typename TQuadEdge>