Maintain keymap editor position when deleting or modifying a binding (#34440)

When a key binding is deleted we keep the exact same scroll bar
position. When a keybinding is modified we select that keybinding in
it's new position and scroll to it.

I also changed save/modified keybinding to use fs.write istead of
fs.atomic_write. Atomic write was creating two FS events that some
scrollbar bugs when refreshing the keymap editor.

Co-authored-by: Ben \<ben@zed.dev\>

Release Notes:

- N/A

crates/settings_ui/src/ui_components/table.rs

@@ -3,8 +3,8 @@ use std::{ops::Range, rc::Rc, time::Duration};
 use editor::{EditorSettings, ShowScrollbar, scroll::ScrollbarAutoHide};
 use gpui::{
     AppContext, Axis, Context, Entity, FocusHandle, Length, ListHorizontalSizingBehavior,
-    ListSizingBehavior, MouseButton, Task, UniformListScrollHandle, WeakEntity, transparent_black,
-    uniform_list,
+    ListSizingBehavior, MouseButton, Point, Task, UniformListScrollHandle, WeakEntity,
+    transparent_black, uniform_list,
 };
 use settings::Settings as _;
 use ui::{
@@ -90,6 +90,28 @@ impl TableInteractionState {
         })
     }
 
+    pub fn get_scrollbar_offset(&self, axis: Axis) -> Point<Pixels> {
+        match axis {
+            Axis::Vertical => self.vertical_scrollbar.state.scroll_handle().offset(),
+            Axis::Horizontal => self.horizontal_scrollbar.state.scroll_handle().offset(),
+        }
+    }
+
+    pub fn set_scrollbar_offset(&self, axis: Axis, offset: Point<Pixels>) {
+        match axis {
+            Axis::Vertical => self
+                .vertical_scrollbar
+                .state
+                .scroll_handle()
+                .set_offset(offset),
+            Axis::Horizontal => self
+                .horizontal_scrollbar
+                .state
+                .scroll_handle()
+                .set_offset(offset),
+        }
+    }
+
     fn update_scrollbar_visibility(&mut self, cx: &mut Context<Self>) {
         let show_setting = EditorSettings::get_global(cx).scrollbar.show;