snippets: Add icons and file names to snippet scope selector (#30212)

I added the language icons to the snippet scope selector so that it
matches the language selector.

The file names are displayed for each scope where there is a existing
snippets file since it wasn't clear if a scope had a file already or
not.

| Before | After |
| - | - |
|
![before](https://github.com/user-attachments/assets/89f62889-d4a9-4681-999a-00c00f7bec3b)|
![after](https://github.com/user-attachments/assets/2d64f04c-ef8f-40f5-aedd-eca239c960e9)
|


Release Notes:

- Added language icons and file names to snippet scope selector

---------

Co-authored-by: Kirill Bulatov <kirill@zed.dev>

crates/snippet_provider/src/lib.rs

@@ -144,15 +144,13 @@ struct GlobalSnippetWatcher(Entity<SnippetProvider>);
 
 impl GlobalSnippetWatcher {
     fn new(fs: Arc<dyn Fs>, cx: &mut App) -> Self {
-        let global_snippets_dir = paths::config_dir().join("snippets");
+        let global_snippets_dir = paths::snippets_dir();
         let provider = cx.new(|_cx| SnippetProvider {
             fs,
             snippets: Default::default(),
             watch_tasks: vec![],
         });
-        provider.update(cx, |this, cx| {
-            this.watch_directory(&global_snippets_dir, cx)
-        });
+        provider.update(cx, |this, cx| this.watch_directory(global_snippets_dir, cx));
         Self(provider)
     }
 }