editor: Add setting for snippet sorting behavior for code completion (#29429)

Added `snippet_sort_order`, which determines how snippets are sorted
relative to other completion items. It can have the values `top`,
`bottom`, or `inline`, with `inline` being the default.

This mimics VS Code’s setting:
https://code.visualstudio.com/docs/editing/intellisense#_snippets-in-suggestions

Release Notes:

- Added support for `snippet_sort_order` to control snippet sorting
behavior in code completion menus.

crates/editor/src/editor.rs

@@ -4733,6 +4733,8 @@ impl Editor {
             .as_ref()
             .map_or(true, |provider| provider.filter_completions());
 
+        let snippet_sort_order = EditorSettings::get_global(cx).snippet_sort_order;
+
         let id = post_inc(&mut self.next_completion_id);
         let task = cx.spawn_in(window, async move |editor, cx| {
             async move {
@@ -4780,6 +4782,7 @@ impl Editor {
                         position,
                         buffer.clone(),
                         completions.into(),
+                        snippet_sort_order,
                     );
 
                     menu.filter(
@@ -8229,10 +8232,18 @@ impl Editor {
         let buffer_id = selection.start.buffer_id.unwrap();
         let buffer = self.buffer().read(cx).buffer(buffer_id);
         let id = post_inc(&mut self.next_completion_id);
+        let snippet_sort_order = EditorSettings::get_global(cx).snippet_sort_order;
 
         if let Some(buffer) = buffer {
             *self.context_menu.borrow_mut() = Some(CodeContextMenu::Completions(
-                CompletionsMenu::new_snippet_choices(id, true, choices, selection, buffer),
+                CompletionsMenu::new_snippet_choices(
+                    id,
+                    true,
+                    choices,
+                    selection,
+                    buffer,
+                    snippet_sort_order,
+                ),
             ));
         }
     }