Implement "TPA-RFC-55: Swap file policy" in Tails servers

TPA-RFC-55 says we should have swapfiles in all systems:

• 1GB for physical machines
• 512MB for everything else

Hosts:

• apt-proxy.lizard
• apt.lizard
• bittorrent.lizard
• chameleon.tails.net
• dns.lizard
• dragon.tails.net
• ecours.tails.net
• gecko.tails.net
• gitlab-runner-3.lizard
• gitlab-runner.iguana
• iguana.tails.net
• isoworker1.dragon
• isoworker2.dragon
• isoworker3.dragon
• isoworker4.dragon
• isoworker5.dragon
• isoworker6.iguana
• isoworker7.iguana
• isoworker8.iguana
• isoworkers-mail.iguana
• jenkins.lizard
• lizard.tails.net
• mail.lizard
• misc.lizard
• mta.chameleon
• proxy-dev.skink
• puppet-git.lizard
• puppet.lizard
• rsync.lizard
• skink.tails.net
• teels.tails.net
• translate.lizard
• whisperback.lizard
• www2.chameleon
• www.lizard

Follow-ups:

• Consider reviewing the sizes of:
  • translate.lizard (1024M > 512M)
  • puppet-git.lizard (4G > 512M)
  • mail.lizard (980M > 512M)
  • skink.tails.net (1.9G > 1G)
  • iguana.tails.net (7.4G > 1G)
  • gecko.tails.net (976M > 512M)
  • apt-proxy.lizard (1024M > 512M)