#111 Refactor workflow definition API endpoints for clearer DSL access

Current endpoints return both JSON and Python DSL in single response. Need separate, clearer endpoints: - GET /api/v1/workflows/definitions/json/<id> - Returns JSON definition only - GET /api/v1/workflows/definitions/dsl/python/<id> - Returns Python DSL source only Tasks: 1. Add new endpoints to api/blueprints/v1/workflows.py 2. Add tests for these APIs (none exist currently) 3. Keep backward compatibility with existing endpoints