Add a changelog for the new CutFEM functionality in NonMatching.

doc/news/changes/major/20220529StickoBergbauerKronbichler

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+New: Several classes have been added to the NonMatching namespace for using cut finite element methods (CutFEM):
+<ul>
+  <li>
+    MeshClassifier identifies how active cells and faces are located relative to the zero contour of a level set function, by associating one of the values of the enum LocationToLevelSet: {inside, outside, intersected}, with each cell/face.
+  </li>
+  <li>
+    QuadratureGenerator creates immersed quadrature rules over the 3 regions of a BoundingBox defined by the sign of a level set function. FaceQuadratureGenerator creates the same type of quadratures but over a face of a BoundingBox. DiscreteQuadratureGenerator and DiscreteFaceQuadratureGenerator create the same type of quadratures over a cell/face when the level set function lies in a finite element space.
+  </li>
+  <li>
+    FEImmersedSurfaceValues is a FEValues-like class for evaluating real space values based on an ImmersedSurfaceQuadrature, i.e., for integrating over the zero contour in a cell.
+  </li>
+  <li>
+    NonMatching::FEValues simplifies assembling by creating dealii::FEValues- and FEImmersedSurfaceValues-objects initialized with the 3 different immersed quadratures of a cell. Analogously, NonMatching::FEInterfaceValues creates dealii::FEInterfaceValues-objects initialized with immersed quadrature rules over a face.
+  </li>
+</ul>
+
+<br>
+(Simon Sticko, Maximilian Bergbauer, Martin Kronbichler, 2022/05/29)