Device:
- fixed problem with subscription handling

Common:
- added slice to EventTools

OFC'22 tests:
- corrected OFC'22 delete service test to identify appropriate service to be deleted
- removed usage of events for testing

Compute:
- remove diversity constraint when not populated

Device:
- removed unused field in database and code polishing

Service:
- migrated L3NMEmulatedServiceHandler to the new API
- polishing of code

- Migrated to use new generic gRPC servicer
- Migrated to use new generic Rest servicer
- Migrated to use new settings framework
- Migrated tests to use new generic servicers and mock's
- Solved bug with endpoint monitors' population (dupplicated sample types due to wrong key generation)
- Use Emulated driver when both driver and device type are not specified
- Separated unitary tests and execution scripts per device driver
- Extracted common unitary test functionalities into separate code files
- Minor code styling/formatting

- support definition of KPISampleTypes per EndPoint in Context and Device
- improvements in definition of objects used for test cases
- adapted few values in unit tests
- updated gRPC-generated Python code for OpticalCentralizedAttackDetector

Common:
- added ORM helper function get_related_instances
- minor modifications in ORM framework

Proto:
- field/message/enum renamings in context.proto to normalize notation

Context:
- Expanded service/database/Models.py into separate models to facilitate coding
- Completed implementation of Get/Set/List/Remove methods for Context, Topology, Device, Link, and EndPoint; also completed for relation models between topology and device/link, and ConfigModels
- Implemented test units for Get/Set/List/Remove methods for Context, Topology, Device, Link, and EndPoint
- Implemented skeleton for Get/Set/List/Remove methods for Service.
- Added Tools.py with helper methods to fimplify handling of enums between ORM and gRPC messages.