Adapted Service to common proto folder

- Moved imports from *.proto folder to common.proto folder
- Removed service's genproto.sh script
- Minor code and linting fixing
- Arranged requirements to accelerate Docker image creation
- Updated Dockerfile
- Arranged GitLab CI/CD pipeline
- Corrected usage of ConfigRules to use new custom ConfigRules
- Removed redundant/unused Tools file in service_handlers