Hide current speed in onroad UI

Added toggle to hide the current speed from the onroad UI and an additional function to enable/disable it by clicking on it via the onroad UI.

selfdrive/ui/ui.cc

@@ -321,6 +321,8 @@ void ui_update_frogpilot_params(UIState *s) {
 
   bool quality_of_life_visuals = params.getBool("QOLVisuals");
   scene.full_map = quality_of_life_visuals && params.getBool("FullMap");
+  scene.hide_speed = quality_of_life_visuals && params.getBool("HideSpeed");
+  scene.hide_speed_ui = scene.hide_speed && params.getBool("HideSpeedUI");
 }
 
 void UIState::updateStatus() {