* Fix a pause in the event loop when clicking the title bar on windows
When clicking the title bar on Windows, to drag the window, there is
a noticible pause in continuous redraw requests. This was fixed
in #839 and then regressed in #1852. The cursor blinks in both
cases and is unrelated. The regression made the blink happen after
the pause instead of immediately.
* Update the event loop pause note on the WM_NCLBUTTONDOWN handler
The application example was also updated to optionally animate the fill color
in order to demonstrate continuous redraw without pauses in the event
loop.
* Rename `WindowEvent::Resized` to `SurfaceResized`
* Rename `InnerSizeWriter` to `SurfaceSizeWriter`
* Replace `inner_size` with `surface_size`
* Rename `resize_increments` to `surface_resize_increments`
This should allow us to make future split of backends much easier.
The `Box<dyn Window>` is a _temporary_ solution, which will be
removed with the future updates when we decide on how the Window
should be stored.
Fixes issue on Wayland due to drop order, since TLS is being dropped
after the event loop, while it shouldn't. In particular it fixes the
crash in the window_run_return example.
