ENH: include <algorithm> in stdFoam.H

- was already included in many places (via UList.C templates), but now
  formalise by placing in stdFoam.H

applications/test/List2/Test-List2.C

@@ -40,8 +40,6 @@ Description
 #include "OFstream.H"
 #include "cpuTime.H"
 
-#include <initializer_list>
-
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 using namespace Foam;