Don't send webxdc notification for notify: "*" when chat is muted

[Amzd]

• webxdc notify specifically to Bob: notifies Bob even when chat is muted
• webxdc notify to everyone ("*"): notifies Bob if he does not have the chat muted

This aligns with how we handle notifications with quote replies.

[iequidoo]

Would be good to add a test, but i think this doesn't block merging

[Amzd]

This was about the limit of my current ability in rust but for testing I used this webxdc app:
@everyone.zip (just change the filename to .xdc as github only supports .zip uploads)

• create group chat
• mute group chat
• share the @everyone webxdc
• on other device click the button in the webxdc app (which triggers notify: "*")
• don't receive push notification (since this PR)