Consider including mumble-server and mumble in Tails

Originally created by @sajolida on #11241 (Redmine)

So we know have a script to run a mumble server in Tails (#9993 (closed)) and anonym got so excited that he wrote a branch to include it in Tails (#9993 (comment 74231)).

Having VoIP support (#5709) has been on our roadmap for years and this branch could solve this.

This ticket is meant to discuss whether:

• Mumble qualifies as a good-enough VoIP solution for the use cases we want to support.
• What needs to be done before the branch feature/mumble is good enough.

Feature Branch: feature/mumble

Attachments

• mumble-expose-cert-digest.png

Parent Task: #5709

Related issues

• Related to #6222 (closed)
• Related to #11551 (closed)
• Related to #5688 (closed)
• Blocked by #9993 (closed)