Implements move execution for battle

PkmnLib.Dynamic/ScriptHandling/ScriptExecution.cs

@@ -25,6 +25,10 @@ public static class ScriptExecution
         }
     }
 
+    /// <summary>
+    /// Executes a hook on all scripts in a list of sources. Note that this does not walk through the parents of the
+    /// sources, but only the sources themselves.
+    /// </summary>
     public static void RunScriptHook(this IReadOnlyList<IEnumerable<ScriptContainer>> source, Action<Script> hook)
     {
         foreach (var container in source.SelectMany(x => x))