add WguiFontSystem, remove FONT_SYSTEM singleton, custom fonts, add Light font weight

there are a few gzip-compressed ttf as for now, looks like variable fonts aren't parsed properly by cosmic_text. Not sure why. Also, we probably need to have a fallback for CJK characters in the future, or just fallback to the built-in ones in the OS.

wgui/src/components/checkbox.rs

@@ -8,9 +8,9 @@ use crate::{
 	animation::{Animation, AnimationEasing},
 	components::{Component, ComponentBase, ComponentTrait, InitData},
 	drawing::Color,
-	event::{CallbackDataCommon, EventAlterables, EventListenerCollection, EventListenerID, EventListenerKind},
+	event::{CallbackDataCommon, EventListenerCollection, EventListenerID, EventListenerKind},
 	i18n::Translation,
-	layout::{self, LayoutState, WidgetID, WidgetPair},
+	layout::{self, WidgetID, WidgetPair},
 	renderer_vk::text::{FontWeight, TextStyle},
 	widget::{
 		ConstructEssentials, EventResult,
@@ -53,6 +53,7 @@ struct State {
 
 #[allow(clippy::struct_field_names)]
 struct Data {
+	#[allow(dead_code)]
 	id_container: WidgetID, // Rectangle, transparent if not hovered
 
 	//id_outer_box: WidgetID, // Rectangle, parent of container

wgui/src/components/mod.rs

@@ -17,6 +17,7 @@ pub struct InitData<'a> {
 // common component data
 #[derive(Default)]
 pub struct ComponentBase {
+	#[allow(dead_code)]
 	lhandles: Vec<EventListenerID>,
 }
 

wgui/src/components/slider.rs

@@ -53,7 +53,8 @@ struct State {
 }
 
 struct Data {
-	body: WidgetID,                  // Div
+	#[allow(dead_code)]
+	body: WidgetID, // Div
 	slider_handle_rect_id: WidgetID, // Rectangle
 	slider_text_id: WidgetID,        // Text
 	slider_handle_node: taffy::NodeId,