Support new files|volumes spec with score-go v1.10.0

[mathieu-benoit]

github.com/score-spec/score-go v1.10.0

score-spec/score-go#103 based on score-spec/spec#123 (comment)

This PR also makes sure that previous/old files|volumes spec is still working while we support the new spec.

Both examples working with this new version (and are not generating any diff with their compose.yaml files):

Old files|volumes spec:

apiVersion: score.dev/v1b1
metadata:
  name: hello-world
containers:
  hello:
    image: .
    files:
      - target: /fileB.txt
        content: |
          I am ${metadata.name}
    volumes:
      - target: /data
        source: ${resources.data}
resources:
  data:
    type: volume

New files|volumes spec:

apiVersion: score.dev/v1b1
metadata:
  name: hello-world
containers:
  hello:
    image: .
    files:
      "/fileB.txt":
        content: |
          I am ${metadata.name}
    volumes:
      "/data":
        source: ${resources.data}
resources:
  data:
    type: volume

[mathieu-benoit]

I think that's it, ready for your review @astromechza please, thanks!

[astromechza]

LGTM just needs a mod tidy