Inline control-config in evidence definition

## CALM Schema Change Proposal

### Target Schema:

evidence.json

### Description of Change:

Enable inlining the declaration of control configs in evidence files

### Use Cases:

Enables control configs to be declared in evidence files without needing hosting or remote storage

### Current Limitations:

As we have enabled the declaration of configs in calm docs to be inline, it makes sense for similar reasons to do so in evidence docs.

### Backward Compatibility:

All docs will still be backward

### Validation Strategy:

Change will be oneOf as is in control.json hence would still be valid

### Implementation Impact:

No impact

### Version Strategy:

Minor in current draft

### Implementation Checklist:

- [ ] Schema changes drafted and validated
- [ ] Example documents created that validate against the new schema
- [ ] Tests written to verify schema behavior
- [ ] Documentation updated to reflect changes
- [ ] Migration guide created (if applicable)
- [ ] Related schemas updated (if applicable)

### Additional Context:

...add any other context, diagrams, or examples about the schema change here...

Start by comparing evidence.json with control.json and the existing inline configuration support in CALM documents. Draft and validate the oneOf schema change, then create example evidence documents and tests covering inline and existing forms. Done means the examples validate, schema behavior is tested, and the relevant documentation is updated.

Written by the indexing model from the issue text.