feat: added support for multiple containers in the same workload

[astromechza]

Description

This PR improves score-compose by allowing it to support multiple containers in the workload and still support published ports and services.

For example, running an api server and a backend worker in the same workload:

apiVersion: score.dev/v1b1
metadata:
  name: my-project

service:
  ports:
    api:
      port: 80
      targetPort: 8080
containers:
  api:
    image: my-project/my-image:0.0.1
    args: ["api"]
  worker:
    image: my-project/my-image:0.0.1
    args: ["worker"]

This produces a compose file that looks like:

services:
  my-project-api:
    command:
      - api
    image: my-project/my-image:0.0.1
    ports:
      - target: 8080
        published: "80"
  my-project-worker:
    command:
      - worker
    image: my-project/my-image:0.0.1
    network_mode: service:my-project-api

Note that the services have a container name appended, the ports are only present on the first service, and the other services inherit the network from the first.

What does this PR do?

1. Add all containers as services to the compose project
2. Add the container name as a suffix to build the service names
3. Share the first services network with the remaining services to ensure port resolution works as expected

Note, (3) emulates what Kubernetes and other "pod"-style runtimes do by placing all containers into the same network namespace, thus no two containers in the same workload can bind to the same port! The advantage though is that the published ports do not need to indicate a particular container.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• New chore (expected functionality to be implemented)

Checklist:

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• I've signed off with an email address that matches the commit author.

[chrishumanitec]

LGTM