Use app.setBadgeCount on linux to show total message count

[flying-sheep]

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• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Problem Description

I like seeing unread message counts in my applications and Ferdium doesn’t seem to show one

Proposed Solution

https://www.electronjs.org/docs/latest/api/app#appsetbadgecountcount-linux-macos

Alternatives Considered

none

Additional Information

No response