Fixed a11y issues for dropdown, profile and submenu components.

Checklist

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Merge Requests for the same update/change?
• Does your submission pass tests?
• Have you lint your code locally prior to submission

Description

Fixed various accessibility issues with the dropdown, profile and various menu components.

Related Issue

N/A

Motivation and Context

This library needs to be completely accessible, and this merge request helps us achieve this goal.

How Has This Been Tested?

Tested in the browser with a keyboard with Digital Shopfront CMS

Accessibility Tests Run (required)

Tested all relevant components with the keyboard.

Tests Added (if applicable)

N/A

Documentation Needed (if Applicable)

N/A

Screenshots (if appropriate):

N/A