fix(tooltips): keep dynamic tooltips from resetting hover delay

Cache ALabel tooltip markup and provide it through query-tooltip instead of repeatedly setting GtkWidget's tooltip-markup property. This prevents frequently updating modules from restarting GTK's display-wide tooltip timer.

Keep the active tooltip updated directly so dynamic tooltip contents continue refreshing while the pointer remains stationary.

include/ALabel.hpp

@@ -4,6 +4,7 @@
 #include <fmt/format.h>
 #include <glibmm/markup.h>
 #include <gtkmm/label.h>
+#include <gtkmm/tooltip.h>
 #include <json/json.h>
 
 #include <optional>
@@ -92,6 +93,7 @@ class ALabel : public AModule {
   // no collation weight, so two different icons compare equal.
   std::optional<std::string> last_label_markup_;
   std::optional<std::string> last_tooltip_markup_;
+  Glib::RefPtr<Gtk::Tooltip> active_tooltip_;
 };
 
 }  // namespace waybar