console.lua: increase the font and border size

Make the console easier to read because the current default is too
small. See for example
https://github.com/mpv-player/mpv/discussions/14903#discussioncomment-10794701
or https://github.com/mpv-player/mpv/pull/15036#discussion_r1794178379
or https://github.com/mpv-player/mpv/pull/15145#issuecomment-2428762898
or https://github.com/mpv-player/mpv/pull/15031#issuecomment-2402289600.

This also prevents libass from decreasing performance by printing many
lines.

player/lua/console.lua

@@ -18,8 +18,8 @@ local assdraw = require 'mp.assdraw'
 -- Default options
 local opts = {
     font = "",
-    font_size = 16,
-    border_size = 1,
+    font_size = 24,
+    border_size = 1.5,
     scale_with_window = "auto",
     case_sensitive = true,
     history_dedup = true,