Prepare a release system for OVF images

[teon]

OVF is an open standard well documented of virtual images.
Some of our customer would like to have those images to easly and quickly deploy defguard in their infrastructure on Proxmox/VMWARE/etc..

Steps to prepare the pipeline:

• research ways of automated OVF building methods
• implement POC OVF building for one of the components
• Build a single OVF that is configured by cloud-init:
  • if it's a gateway, proxy, core...
  • network through cloud-init
  • on core the URL of proxy through cloud-init
  • on gw the URL of core through cloud-init
  • initiate a Certificate Authority on core
  • research how to spread the certificate for GW & proxy for gRPC as well as reverse-proxy

The current POC is available in the deployment repository: https://github.com/DefGuard/deployment/tree/ovf/ovf