Kalatori daemon staging instance

[Vovke]

With every new version of Kalatori we build docker image which we push to docker hub.
The easiest way would be just to leverage docker compose in order to run it on the instance.

In order to create a GHA for staging instance release I need following:

• low tirer instance 2 CPU, 2GB RAM, 20 GB storage or equivalent
• instance should run ubuntu:latest with docker and docker compose preintalled
• the instance should expose 22 and 16726 ports
• the instance should be accessible at kalatori-staging.zymologia.fi
• instance host address
• instance user
• instance ssh key

follow up tasks:

• Setup cron to cleanup images on staging instance #162
• Restrict staging instance 22 port to specific IPs (CI/CD range) #163
• Setup staging instance basic monitoring and logging #164