Remove some Dune::VirtualFunction related stuff
This removes some function implementations based on the deprecated Dune::VirtualFunction interface and related utilities and tests:
-
SumFunction(replacement: lambda function) -
SumGridFunction(replacement:Dune::Functions::ComposedGridFunctionwith lambda function) -
ComposedFunction(replacement: lambda function) -
ComposedGridFunctional(replacement:Dune::Functions::ComposedGridFunctionwith lambda function) -
Polynomial(replacement:Dune::Functions::Polynomial) -
NamedFunctionMap(replacement:std::map<std::string, std::function<Range(Domain)>>)