help docker-runner compatible with modelpack

[aftersnow]

Feature request:

See: docker/model-spec#3

[aftersnow]

This requires a PR to the model-runner, to help compatible with modelpack/model-spec

[github-actions]

This issue is stale because it has been open 40 days with no activity.

[github-actions]

This issue was closed because it has been stalled for 7 days with no activity.

[bergwolf]

There initial modelpack support has been merged in docker model runner: docker/model-runner#516

The leftover being:

• Add E2E test in docker model runner to validate the implementation
• Add documentation in both docker/model-runner and ModelPack/model-spce repos to show how users can use it
• OPTIONAL: Add downstream users compatibility validation tests in model-spec to ensure we do not break backward compabitiliy by accident (for modctl/kitops/model-runner/aikit?)