Move DoAudacityCommand out of PluginMenus

src/BatchCommands.h

@@ -54,6 +54,9 @@ private:
 // Stores information for one macro
 class MacroCommands final {
  public:
+   static bool DoAudacityCommand(
+      const PluginID & ID, const CommandContext & context, unsigned flags );
+
    // constructors and destructors
    MacroCommands();
  public: