refactor: improve code

...ins/deadlock-extension/resources/js/gettingStartedView.js

...eadlock-extension/resources/styles/gettingStartedView.css

deadlock-plugins/deadlock-extension/src/core/api.service.ts

...ock-plugins/deadlock-extension/src/core/commandHandler.ts

deadlock-plugins/deadlock-extension/src/core/controller.ts

deadlock-plugins/deadlock-extension/src/core/gitMission.ts

.../src/core/keycloakOAuth2DeviceFlowConnectionVSCodeImpl.ts

...k-plugins/deadlock-extension/src/core/metadataProvider.ts

deadlock-plugins/deadlock-extension/src/extension.ts