Refactor Puppet code for Jenkins from www.lizard

Originally created by @intrigeri on #7107 (Redmine)

See parent ticket for the rationale.

https://github.com/boklm/puppet-sshkeys will probably be needed.

Parent Task: tails/sysadmin#6056

Related issues

• Related to tails/sysadmin#8912
• Related to #9616 (closed)