Merge branch 'fix/ElementGridFunctionWithNonNumberData' into 'master'

Fix/element grid function with non number data

See merge request amdis/amdis!214

amdis/gridfunctions/ElementGridFunction.hpp

@@ -95,7 +95,7 @@ namespace AMDiS
     IndexSet const* indexSet_;
     Container const* container_;
     std::optional<Element> element_;
-    Range value_ = 0;
+    Range value_ = {};
   };