workspace taskbars: Display windows in a consistent order

Use a vector instead of a map for for storing the workspace windows.
This orders the windows by the time they were added to the workspace, instead of sorting by address (which is effectively a random order). The new ordering seems to match the wlr/taskbar module

include/modules/hyprland/windowcreationpayload.hpp

@@ -27,6 +27,7 @@ namespace waybar::modules::hyprland {
 class Workspaces;
 
 struct WindowRepr {
+  std::string address;
   std::string window_class;
   std::string window_title;
   std::string repr_rewrite;