core/menusystem: add a basic text widget

sonic-boost.love/core/modules/menusystem/widgets/init.lua

@@ -1,6 +1,7 @@
 local Widget = {}
 
 BaseWidget  = Object:extend()
+TextWidget  = BaseWidget:extend()
 
 function BaseWidget:new(menu)
   self.menu = menu
@@ -75,6 +76,23 @@ function BaseWidget:destroy()
   self.destroyed = true
 end
 
+-- Simple text widget
+
+function TextWidget:new(menu, font, label)
+  TextWidget.super.new(self, menu)
+  self.font = font
+  self.label = label
+end
+
+function TextWidget:drawCanvas()
+  local w, h
+  w = math.floor(self.width / 2)
+  h = math.floor(self.height / 2) - (self.font:getHeight() / 2)
+  self.font:draw(self.label, w, h, -1, "center")
+end
+
+
 Widget.Base   = BaseWidget
+Widget.Text   = TextWidget
 
 return Widget