- Added/Updated headers
- Added script to update copyright headers

- disabled event testing; operation works, but sometimes tests get stuck
- added dynamic wait for CockroachDB and NATS containers to start
- tuned grace shutdown period
- improved NatsBackend termination

- corrected unitary test order and one-by-one execution
- extractedunitary test constant to separate file
- added updated_at refresh for Service and Slice entities
- corrected return types for Connection entity
- prepared PolicyRule entity to raise events and corrected return types of methods

- configured constant with event collection timeout for unitary tests and debug purposes
- cosmetic changes
- migrated event reporting for Connection entity

- migrated events for Service and Slice entities
- added missing not-nulls to database fields

- removed old code
- implemented basic support for Slice entity
- implemented detailed perf eval report in unitary tests