Adding or removing items from navigation menus needs audible notification.

[joedolson]

The customizer announces that items have been added or removed from navigation as an audible alert for screen readers after the action is performed, but the menu management at Appearance > Menus does not.

Needs wp.a11y.speak notices added to announce those confirmations.

Issue originally noted in #49876, now being broken out to isolate action on this topic.

[costdev]

Hi @joedolson, I see this is accepted - Are you working on this solo or is it alright for me to submit a PR for review?

[joedolson]

You can absolutely submit a PR, @costdev!

Trac ticket: https://core.trac.wordpress.org/ticket/53840

[hellofromTonya]

Hey @joedolson, the qunit tests now pass. The globals needed to be mocked for the nav tests (whereas they are available when running it live).

I'll mark it for commit as ​I thought you said you had already checked that it works as expected (i.e. only the tests passing remained).

[joedolson]

Thanks! Yes, this worked in browser testing as expected.

[joedolson]

Minor changes/fixes:

• Changed removal text to 'Item Removed', to match the text of the control that triggers the message.
• Removed duplicate wp.a11y.speak call on item removal (called in eventOnClickMenuItemDelete and in removeMenuItem, but eventOnClickMenuItemDelete calls removeMenuItem, so that creates a duplicate message.)

[joedolson]

Update patch to remove duplicate .speak call & change text strings

[joedolson]

In 52166:

Menus: Add audible notice on menu item add or remove.

Call wp.a11y.speak() to add audible notification when a menu item is added or removed from a menu.

Props joedolson, costdev, hellofromTonya.
Fixes #53840.