Add missing include in ComposedGridFunction
Without this, the typedef using Traits = Imp::GridFunctionTraits<Range(Domain), EntitySet, DefaultDerivativeTraits, 16>;
and some others might not be declared in time.
Without this, the typedef using Traits = Imp::GridFunctionTraits<Range(Domain), EntitySet, DefaultDerivativeTraits, 16>;
and some others might not be declared in time.