git: New enter behaviour (#25986)

Closes #25951

Release Notes:

- git: Update "enter" in the list of changed files to preserve focus. If
you want the old behaviour, hit enter twice.
- git: Follow the cursor, not the scroll anchor, in the list. Although
the scroll anchor was nice for passive scrolling, it broke if you had
changed the overflow scroll settings.

crates/editor/src/element.rs

@@ -2722,7 +2722,10 @@ impl EditorElement {
                     .shadow_md()
                     .border_1()
                     .map(|div| {
-                        let border_color = if is_selected && is_folded {
+                        let border_color = if is_selected
+                            && is_folded
+                            && focus_handle.contains_focused(window, cx)
+                        {
                             colors.border_focused
                         } else {
                             colors.border