## Description

This PR expands the items displayed in the overflow menu of a `TextSelectionToolbar` making buttons clickable in the blank area.

| Before | After |
|--------|--------|
| Each item has its own width | All items expand horizontally |
|  ![Capture d’écran 2024-02-29 à 14 43 57](https://github.com/flutter/flutter/assets/840911/f7379eef-9185-4cc4-bf14-e4c916c432b1) | ![Capture d’écran 2024-02-29 à 14 40 47](https://github.com/flutter/flutter/assets/840911/bff272cd-9fe2-4f07-adaf-61edef03d26e) | 

## Related Issue

Fixes https://github.com/flutter/flutter/issues/144089.

## Tests

Adds 1 tests.