Deploy a VPN between the monitoring host and Lizard

Originally created by @bertagaz on #11094 (Redmine)

As stated in tails/sysadmin#10760, the best option to interconnect our different hosts is to use a VPN. Tinc seems to be the simpler option for that.

Feature Branch: puppet-tails:feature/11094-tails-vpn

Parent Task: tails/sysadmin#5734

Edited May 15, 2020 by bertagaz