- made frontend a module

- Arranged GitLab CI/CD
- Relocated test files

- Added curl as dependency for unitary tests
- Added configuration settings in Frontend
- Removed unneeded logs

- Arranged GitLab CI/CD
- Added log messages

- Arranged GitLab CI/CD and Docker build
- Configured code coverage
- Grouped test scripts
- Instrumented source code and Makefile for code coverage reporting

- Arranged ports in GitLab CI/CD unitary tests
- Added env-var dump for tests

Unitary test:
- Corrected Objects definition
- Added devices and links to topology

Frontend component:
- Implemented parsing of backend reply and composition of front-end reply
- Other minor arrangements

- implemented delete of IETF L2VPN services/slices
- implemented diversity and availability constraints

- implemented skeleton for L2VPN service handlers for emulated devices

- refined create/update of slices
- implemented delete of slices

- fixed parsing of custom rules in unitary tests

- Added missing log dump in unitary test

- added exposition of redis-tests service for testing with Redis backend
- moved delete logic from Context Servicer to ORM components
- added support for constraints of different kinds

- added helper methods to copy/update grpc messages: config_rules, constraints, endpoint_ids, service_ids
-  extended Context ConstraintModel to support different types of constraints
- extended EndpointModel with get_endpoint helper method
- extended SliceModel to incorporate config rules

- arranged run_test scripts and objects
- deactivated unneeded components in the deployment
- arranged LoadDescriptors Python script
- improved Tutorial page for ECOC'22 demo