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.