Geometry: Make meshing method to undo command.

src/View/Geometry/Table.py

@@ -221,3 +221,15 @@ class GeometryReachTableModel(PamhyrTableModel):
 
         self.layoutAboutToBeChanged.emit()
         self.layoutChanged.emit()
+
+    def meshing(self, mesher, step):
+        self.layoutAboutToBeChanged.emit()
+
+        self._undo.push(
+            MeshingCommand(
+                self._data, mesher, step
+            )
+        )
+
+        self.layoutAboutToBeChanged.emit()
+        self.layoutChanged.emit()