feat(e2e-test): test for custom model spec & inference via HTTP/gRPC

[domsolutions]

Summary of changes

• added new test for deploying models via custom yaml - for when testers don't want to use pre-packaged models
• tests for inference on http/gRPC
• removed the circular dependency between model/world by using closure

Checklist

• Added/updated unit tests
• Added/updated documentation
• Checked for typos in variable names, comments, etc.
• Added licences for new files

Testing

[MiguelAAe]

LGTM