add --show-extras to uv tool list to list extra requirements installed with tools (#13783)

## Summary

Implemented as suggested in #13761 

eg.

```
$ uv tool install 'harlequin[postgres]'
$ uv tool list --show-extras
harlequin v2.1.2 [extras: postgres]
- harlequin
```

## Test Plan

Added a new test with the argument along with the others from the `uv
tool list` cli.

crates/uv-cli/src/lib.rs

@@ -4419,6 +4419,10 @@ pub struct ToolListArgs {
     #[arg(long)]
     pub show_with: bool,
 
+    /// Whether to display the extra requirements installed with each tool.
+    #[arg(long)]
+    pub show_extras: bool,
+
     // Hide unused global Python options.
     #[arg(long, hide = true)]
     pub python_preference: Option<PythonPreference>,