add a __tostring method to every object (#1534)

* added a stupid __tostring to every object

* moved every __tostring to just after the :extend() call

---------

Co-authored-by: Adam <adamdharrison@gmail.com>
(cherry picked from commit 880e7f1fa1521cdf176f44627a27c901e187058e)

data/core/scrollbar.lua

@@ -19,6 +19,8 @@ local Object = require "core.object"
 ---@class core.scrollbar : core.object
 local Scrollbar = Object:extend()
 
+function Scrollbar:__tostring() return "Scrollbar" end
+
 ---@class ScrollbarOptions
 ---@field direction "v" | "h" @Vertical or Horizontal
 ---@field alignment "s" | "e" @Start or End (left to right, top to bottom)
@@ -339,5 +341,4 @@ function Scrollbar:draw()
   self:draw_thumb()
 end
 
-
 return Scrollbar