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/project/src/project.rs

@@ -1023,7 +1023,7 @@ impl Project {
             let (tx, rx) = mpsc::unbounded();
             cx.spawn(async move |this, cx| Self::send_buffer_ordered_messages(this, rx, cx).await)
                 .detach();
-            let global_snippets_dir = paths::config_dir().join("snippets");
+            let global_snippets_dir = paths::snippets_dir().to_owned();
             let snippets =
                 SnippetProvider::new(fs.clone(), BTreeSet::from_iter([global_snippets_dir]), cx);