PolicyAdd rpc replaced by PolicyAddService & PolicyAddDevice

DLT component - updated proto & re-structured

See merge request teraflow-h2020/controller!114

chore(policy): update application.yml

See merge request teraflow-h2020/controller!113

- restructured component and separated it into "connector" and "gateway" subcomponents.
- arranged name typos in DLT proto file
- prepared component folders for dlt-connector component

- Defined new dlt.proto file

feat(policy): create policy domain objects

See merge request teraflow-h2020/controller!108

Policy/update policy protobuf

See merge request teraflow-h2020/controller!111

test(automation): add contextSubscriberTest

See merge request teraflow-h2020/controller!107

feat(policy): add readiness health check

See merge request teraflow-h2020/controller!109

ci(policy): refactor gitlab-ci.yml

See merge request teraflow-h2020/controller!105

New generic client and service interfaces, new settings framework, new unit test scheme

See merge request teraflow-h2020/controller!104

- added missing dependency for unitary tests

- Corrected unitary test to execute pipeline

- corrected unitary test file for device component
- arranged clients used by optical centralized attack detector
- Minor corrections in unitary test of Context component
- corrected skeleton for unitary tests of Slice component

- Migrated to use new generic gRPC servicer and clients
- Migrated to use new settings framework
- Improved definition of unitary tests and solved some bugs
- Minor code formatting/styling

- added helper methods to object_factory

- Migrated to use new generic gRPC servicer and clients
- Migrated to use new settings framework
- Commented wrong/outdated unitary tests (to be coded)
- Minor code formatting/styling

- Migrated to use new generic Rest servicer
- Moved client declarations close to use places to prevent initialization locks
- Adaptations to comply with the new settings framework
- Updated unitary tests to use new generic Rest and gRPC servicers and clients
- Minor code styling/formatting

- Migrated to use new generic gRPC servicer
- Migrated to use new generic Rest servicer
- Migrated to use new settings framework
- Minor code formatting/styling

- Migrated to use new generic gRPC servicer
- Migrated to use new settings framework