VNF Framework Task 7: Implemented service methods with broker integration

- Implemented listVnfDictionaries with filtering by vendor/version
- Implemented create/update/delete firewall rule with VnfBrokerClient and operation tracking
- Implemented createVnfNATRule with response mapping
- Implemented testVnfConnectivity and reconcileVnfNetwork minimal flows
- Implemented operation query methods (by state/instance/ruleId)
- Added helper hashing and response builder

Build: SUCCESS

Author: Build2 CI