Use consistent ordering for popup menus (#27765)

Before this change, the editor completion menu and gutter menus reversed their order so that the initial selection is near the user's focus.  This change instead displays these menus in a consistent top-to-bottom order because the following benefits outweigh that benefit:

* Matches behavior of some other editors (Neovim and VSCode).
* Looks better for lexicographic lists.
* Keeps the meaning of keyboard interaction consistent, if the user is anticipating the order of the menu's contents.

Could consider making this configurable in the future if desired.

Closes #25066.

Release Notes:

- N/A

crates/editor/src/editor.rs

@@ -7702,7 +7702,6 @@ impl Editor {
         &self,
         style: &EditorStyle,
         max_height_in_lines: u32,
-        y_flipped: bool,
         window: &mut Window,
         cx: &mut Context<Editor>,
     ) -> Option<AnyElement> {
@@ -7711,7 +7710,7 @@ impl Editor {
         if !menu.visible() {
             return None;
         };
-        Some(menu.render(style, max_height_in_lines, y_flipped, window, cx))
+        Some(menu.render(style, max_height_in_lines, window, cx))
     }
 
     fn render_context_menu_aside(