Accessibility: make status notifications accessible

[ahmadkadri]

Description: When participants join or leave the conference, this information is shared via a message. This message also appears when new moderation rights are assigned. However, these messages are not programmatically recognized as status updates.

Actual Behavior: The screen reader doesn't read the notification.

Expected Behavior: The notification should be provided for screen reader users.

Before:

beforeOtherUserEnterTheMeeting.mp4

beforeUserJoinTheMeeting.mp4

After:

afterUserJoinTheMeeting.mp4

afterOtherUserEnterTheMeeting.mp4

issue jitsi community: https://community.jitsi.org/t/accessibility-improvement/133102

[jitsi-jenkins]

Hi, thanks for your contribution!
If you haven't already done so, could you please make sure you sign our CLA (https://jitsi.org/icla for individuals and https://jitsi.org/ccla for corporations)? We would unfortunately be unable to merge your patch unless we have that piece :(.

[saghul]

@Calinteodor can you PTAL too?

[Calinteodor]

Jenkins please test this please!

[saghul]

Jenkins please test this please.