Incorrect aria-live announcement when removing a permalink custom structure

[joedolson]

When removing an added custom structure at Settings > Permalinks, the same message is announced as when adding the custom structure, e.g. "year added to permalink structure". The message when removing should instead indicate "year removed from permalink structure".

The button's aria-label is changed to indicate that the element is already used, and that changes after activating the link, but the announced message will give the impression that you have added the structure rather than removing.

This was introduced in changeset:41182.

[joedolson]

Add 'remove' message to permalink structure buttons

[joedolson]

Tested with NVDA/Chrome already.

Testing:

• at Settings > Permalinks, using a screen reader, navigate to custom structure buttons.
• Add a structure to the permalink format, noting announcement '{tag} added to permalink structure'
• Navigate back to same structure, click again to remove. note announcement '{tag} removed from permalink structure'.

[kebbet]

Might need a refresh after all updates to options-permalink.php.

[SergeyBiryukov]

Refreshed after [53710].

[joedolson]

Move setting textToAnnounce back to before it's announced.

[joedolson]

Updated patch & tested with VoiceOver/Safari & JAWS/Firefox. Marking for commit.

[joedolson]

In 53911:

Permalinks: Fix aria-live text when removing custom structure.

Change the notification announced when a custom structure is removed. Previously, the notification incorrectly indicated that the structure was added for both actions. This changes the notification to correctly announce removals when structures are removed.

Props joedolson, kebbet, SergeyBiryukov.
Fixes #56230.