Fix unitary tests to align with changes in monitoring component information model.

Fix monitoring loops to align with changes in monitoring component information model.

Modifications in the monitoring information model and skeleton of the methods...

See merge request teraflow-h2020/controller!163

Update 1-1-1-create-vm-oracle-virtualbox.md to clarify Ubuntu Server should be use instead of Desktop

refactor(policy): add validation at PolicyRuleDevice

See merge request teraflow-h2020/controller!161

refactor(policy): add validation at PolicyRuleService

See merge request teraflow-h2020/controller!160

refactor(policy): add validation at PolicyRuleCondition

See merge request teraflow-h2020/controller!159

- fixed parsing of custom rules in unitary tests

- Added missing log dump in unitary test

Common and Context changes:

See merge request teraflow-h2020/controller!157

- 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

fix(policy): update ConstraintIsolationLevel object

See merge request teraflow-h2020/controller!158

refactor(policy): implement builder pattern for EndPoint

See merge request teraflow-h2020/controller!152

Automation/implement builder pattern for end point

See merge request teraflow-h2020/controller!151

- 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

Extended Context proto files with slice config rules, endpoint priority constraint, and modified isolation level constraint

See merge request teraflow-h2020/controller!156

- Slice: added config rules
- Added EndpointPriority constraint
- Modified IsolationLevel constraint to contain a repetition of items

Arranged deploy scripts

See merge request teraflow-h2020/controller!155

- corrected service name computation in expose_ingress_grpc.sh script
- corrected log format in deploy.sh script
- added control to configure Grafana only when both webui and monitoring are deployed

Added tutorial for debugging with VSCode

See merge request teraflow-h2020/controller!150

- added sections describing installation of Python Extension in VSCode
- added section describing how to export and test connectivity to services through gRPC

refactor(policy): change proto files names

See merge request teraflow-h2020/controller!154