Unify app badge setting/app badges missing

[Roy-Orbison]

Summary

Mattermost used as a Progressive Web App does not show a badge for unread notifications.

Steps to reproduce

1. Log into a Mattermost server in Chrome/Safari on Windows or Mac.
2. Install as a PWA.
3. Get a message.

Operating System

Windows or MacOS

Mattermost Server Version

Any

Expected behavior

To see a badge showing a count of unreads, when applicable, just as the Electron app does.

Observed behavior

No badge shown.

Log Output

n.a.

Additional Information

Electron has been able to use the same API to set badges as a PWA since v12 (about 3 years ago). Support for PWAs is pretty wide. They offer many advantages to the average user: no extra software to install and keep updated, especially if users lack permission to do so; they are often already running a browser that is kept updated, so it reduces system resources; and PWAs can be synched across machines. Moving the code to this repo, and a less proprietary API, seems like an easy win for UX.

Possible fixes

A PR was opened to fix this 20 months ago, but wasn't migrated here.

[amyblais]

Thanks, appreciate your feedback @Roy-Orbison,

Would you like to contribute this in the feature idea forum so it can be discussed, upvoted and considered for a help wanted ticket?

Please include a link back to this GitHub issue. If you're interested in implementing, please say so and we'll prioritize the review.

You get 10 votes in the feature idea forum, and each one influences the future of the project.

[Roy-Orbison]

As per linked PR, it's already in the idea forum, and has an implementation. Does it not work?

[amyblais]

The original community contributor didn't re-submit the PR here and the reviews/testing weren't fully completed in the original PR. For now, the existing Uservoice request can be upvoted, or someone can re-submit the implementation.