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>

Cargo.lock

@@ -14675,11 +14675,14 @@ dependencies = [
 name = "snippets_ui"
 version = "0.1.0"
 dependencies = [
+ "file_finder",
+ "file_icons",
  "fuzzy",
  "gpui",
  "language",
  "paths",
  "picker",
+ "settings",
  "ui",
  "util",
  "workspace",