[Testing] Enhance local runner validation

[dhegberg]

Migration from aws/aws-durable-execution-sdk-python-testing#26

---

Context

Implement backend service worker validation rules in local runner

Technical Requirements

• Implement backend service worker validation rules in local runner
• Add corresponding exception handling for new validation errors
• Update existing tests to handle new validation logic

Acceptance Criteria

• Backend service worker validation rules implemented in local runner
• Exception handling added for new validation errors
• Existing tests updated to handle new validation logic