clean code phase 1

src/context/service/database/Device.py

src/context/service/database/OpticalConfig.py

src/context/service/database/OpticalLink.py

src/device/service/DeviceServiceServicerImpl.py

src/device/service/OpenConfigServicer.py

src/device/service/Tools.py

src/service/service/ServiceServiceServicerImpl.py

src/service/service/service_handler_api/SettingsHandler.py

src/service/service/service_handlers/oc/OCServiceHandler.py

...rvice/service/service_handlers/qkd/qkd_service_handler.py

src/service/service/task_scheduler/TaskExecutor.py

src/service/service/task_scheduler/TaskScheduler.py

src/webui/service/opticalconfig/routes.py