A [must_resize] and [ctx.is_pointer_over_area()] is now used to
indicate we need a resizing. This makes it so when a user is
resizing the width of Gupax, the heavy [init_text_styles()] func
will only get called once when the user hovers over the GUI.
The button size is also now set in that function so it doesn't
have to be called in every separate tab.