a11y: Provide message delivery status through VoiceOver

[kinoroy]

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• iPhone 15 Pro, iOS 18.5
• Simulator, iOS 18.2

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Description

This commit modifies the accessibility label for an outgoing message to provide information on the message delivery status (delivered, sent, read, etc):

This has been reported in multiple issues by VoiceOver users and in the Signal forums:

• Read receipts informations no more accessible via VoiceOver #3955 (closed due to inactivity / stale)
• A11Y: Missing status information for sent messages when using VoiceOver #5883 (closed due to inactivity / stale)
• https://community.signalusers.org/t/improve-signal-for-voiceover-users/68130

It seems based on comments in the code that the omission of this data was on purpose to keep the accessibility label short. I would suggest that users who rely on VoiceOver deserve to get the same level of information that can be obtained by sighted users who are glancing at the message.

Omitting this info from the accessibility label forces VoiceOver users to drill down into submenus and navigate to the message details screen, something a sighted person doesn't have to do to obtain the same information.

By placing this information at the end of the accessibility label, the user can choose to skip to the next element and stop listening if they don't wish to hear this extra information.