Add Terraform setup

[mmsc2]

What ❔

Why ❔

This PR adds the neccessary files to deploy a ZK server into hetzner with terraform. To build the setup it is required to have a hetzner token and set the ssh public key (or keys) inside the user_data.yml.

Inside the infraestructure/terraform directorty execute the following commands:

1. terraform init
2. terraform plan -var='hcloud_token'=<TOKEN>
3. terraform apply -var='hcloud_token'=<TOKEN>

The second step is to check that everything is ok before deploying, it can be skipped.
In order to delete the server, the command terraform destroy -var='hcloud_token'=<TOKEN> can be executed.

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• Code has been formatted via zk fmt and zk lint.

[popzxc]

Closing as stale and unlikely to be merged