[terra-navigation-side-menu] Example Update

[MadanKumarGovindaswamy]

Summary

What was changed:

Updated navigation-side-menu example.

Why it was changed:

Example does not convey name, role, value of the control.

Testing

This change was tested using:

• WDIO
• Jest
• Visual testing (please attach a screenshot or recording)
• Other (please describe below)
• No tests are needed

Reviews

In addition to engineering reviews, this PR needs:

• UX review
• Accessibility review
• Functional review

Additional Details

This PR resolves:

UXPLATFORM-XXXX

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@cerner/terra

[allanxavierm]

@MadanKumarGovindaswamy You may have to resolve the merge conflict here

[rbsree]

+1, the issue mentioned in the PR is fixed.

But there are few issue I found in the Terra Side Menu navigation component.

Issues:

• When an menuitem is selected it SR does read message as "--menuitem, selected", but when user navigates away and back to the selected menutiem the selected state is not exposed to users.
• Back button present in the submenu control doesn't have a contextual label.
• When user lands on 'Hospital Services' sub menu- The instructions to activate with enter / space key is not announced. - (Default behaviour, checked with https://www.w3.org/WAI/ARIA/apg/patterns/menu-button/examples/menu-button-links/)