feat(poc): running in Docker

[rangoo94]

Pull request description

It's just a Proof of Concept, based on some early code from last year. Works without problems for simple workflows though.

• Allow Testkube running executions in Docker
• TODO: parallel syntax doesn't work
• TODO: services syntax doesn't work
• TODO: better error handling and code quality
• TODO: handle FSGroup properly + more K8S syntax
• TODO: Avoid copying Init Process / Toolkit each time -> there could be appropriate shared volume created on start with these binaries

Testing live (agent only)

• Adjust TESTKUBE_PRO_* environment variables in docker-compose.yaml to match your Agent
• Run docker compose up
  • or docker compose watch to get it running and rebuilt on each change
• Run docker compose down -v to clean up

Testing live (incl. Control Plane)

• Adjust ENTERPRISE_LICENSE_KEY environment variable in docker-compose.full.yaml
• Run docker compose -f docker-compose.full.yaml up
  • or docker compose -f docker-compose.full.yaml watch to get it running on rebuilt on each agent change
• Go to https://localhost:8080 and login with admin@example.com/password
  • create test workflow and run it
• Run docker compose -f docker-compose.full.yaml down to clean up

Checklist (choose whats happened)

• breaking change! (describe)
• tested locally
• tested on cluster
• added new dependencies
• updated the docs
• added a test