editor: Represent scroll offset with more precision (#39367)

Closes #5355

Release Notes:

- Fixed rendering glitches with files with more than 16 million lines
(that occured due to floating number rounding errors).

---------

Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>

crates/gpui/src/platform/linux/x11/window.rs

@@ -1204,7 +1204,7 @@ impl PlatformWindow for X11Window {
             self.0.xcb.query_pointer(self.0.x_window),
         )
         .log_err()
-        .map_or(Point::new(Pixels(0.0), Pixels(0.0)), |reply| {
+        .map_or(Point::new(Pixels::ZERO, Pixels::ZERO), |reply| {
             Point::new((reply.root_x as u32).into(), (reply.root_y as u32).into())
         })
     }