gpui: Add restrict_scroll_to_axis to match web scrolling behavior (#25963)

This PR adds a new `restrict_scroll_to_axis` style to allow consumers to
opt-in to the scrolling behavior found on the web.

When this is enabled the behavior will be such that:

- Scrolling using the mouse wheel will only scroll the Y axis
- Scrolling using the mouse wheel with <kbd>Shift</kbd> held will only
scroll the X axis

This behavior is useful in scenarios where you have some
vertically-scrollable content that is interspersed with
horizontally-scrollable elements, as otherwise the scroll will be
constantly hijacked by the horizontally-scrollable elements while trying
to scroll up and down in the vertically-scrollable container.

I think that this behavior should be the default, but it's a bit of a
sweeping change to make all at once, so for now it remains opt-in.

Release Notes:

- N/A

crates/gpui/src/elements/div.rs

@@ -2127,6 +2127,7 @@ impl Interactivity {
         if let Some(scroll_offset) = self.scroll_offset.clone() {
             let overflow = style.overflow;
             let allow_concurrent_scroll = style.allow_concurrent_scroll;
+            let restrict_scroll_to_axis = style.restrict_scroll_to_axis;
             let line_height = window.line_height();
             let hitbox = hitbox.clone();
             window.on_mouse_event(move |event: &ScrollWheelEvent, phase, window, cx| {
@@ -2139,7 +2140,7 @@ impl Interactivity {
                     if overflow.x == Overflow::Scroll {
                         if !delta.x.is_zero() {
                             delta_x = delta.x;
-                        } else if overflow.y != Overflow::Scroll {
+                        } else if !restrict_scroll_to_axis && overflow.y != Overflow::Scroll {
                             delta_x = delta.y;
                         }
                     }
@@ -2147,7 +2148,7 @@ impl Interactivity {
                     if overflow.y == Overflow::Scroll {
                         if !delta.y.is_zero() {
                             delta_y = delta.y;
-                        } else if overflow.x != Overflow::Scroll {
+                        } else if !restrict_scroll_to_axis && overflow.x != Overflow::Scroll {
                             delta_y = delta.x;
                         }
                     }