Merge branch 'feat/context-policy' into 'develop'

src/common/tools/object_factory/PolicyRule.py

src/context/client/ContextClient.py

src/context/service/database/PolicyRuleModel.py

src/context/service/grpc_server/ContextService.py

...context/service/grpc_server/ContextServiceServicerImpl.py

src/context/service/rest_server/Resources.py

src/context/tests/Objects.py

src/context/tests/test_unitary.py