- Updated wait loop time

- Corrected structure of Debug API
- Updated paths and endpoints
- Removed unneeded common constants

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

- Implemented Debug API
- Implementing unitary debug API tests

- updated OFC'22 test scripts with source of env variables
- activated DEBUG logs in Device and Service components
- added Slice as dependency of Compute
- removed creation of services in Compute, all goes through Slice
- Added missing default constraints in PathComp Frontend
- added logic in Slice to identify if its L2 or L3

- Added subfolder rest_server/nbi_plugins/ietf_network_slice
- Modified and created classes to register new URLs in the REST server
- Skeleton for methods GET/POST/DELETE
- Refactoring: moved "tools" subfolder one level up

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

Common:
- added chk_attribute to type_checkers module.
- recovered run_tests_locally.sh

Compute:
- updated requirements.in
- updated Config.py
- updated RestServer
- implemented IETF-L2VPN NBI plugin
- implemented unitary tests for IETF-L2VPN NBI plugin including a Mock OSM client, and Mock Context and Service components

- Added REST API Server to Compute component
- Factorized get settings from environment variabes into common method get_setting

This reverts merge request !3

Move database to common folder, since it will be used also by device service, and implement very minor changes.