Device model updated to SQLAlchemy

src/context/service/Database.py

src/context/service/__main__.py

src/context/service/database/ConfigModel.py

src/context/service/database/ContextModel.py

src/context/service/database/DeviceModel.py

src/context/service/database/EndPointModel.py

src/context/service/database/KpiSampleType.py

src/context/service/database/Tools.py

src/context/service/database/TopologyModel.py

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

src/context/tests/Objects.py

src/context/tests/test_unitary.py