[BUG]: A11y - Content tree caret buttons has no accessible name/role/value

[liamlaverty]

Describe the bug Caret buttons in the left hand menu have no guidance for accessibility users. This fails WCAG 2.0 & 2.1 rule 4.1.2 - name, role, value

To Reproduce Steps to reproduce the behavior:

1. Open the typescript app
2. right click the caret next to the recycle bin
3. inspect element
4. see the HTML content excludes an aria-label:

<button id="caret-button">
              <uui-symbol-expand></uui-symbol-expand>
            </button>

Expected behavior

Carets should be updated to include an aria-label which describes the button's action, for example:

<button id="caret-button" aria-label="Reveal child content nodes">
              <uui-symbol-expand></uui-symbol-expand>
            </button>

Screenshots Screenshot shows where to find a caret in the vite app:

Desktop (please complete the following information):

• OS: macOS Sonoma 14.2.1 (23C71)
• Browser MS Edge
• Version 122.0

Additional context Add any other context about the problem here.