refactor: improve extension source code

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

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

...ck-plugins/deadlock-extension/src/core/mission/mission.ts

...eadlock-extension/src/core/mission/missionDevContainer.ts

...eadlock-extension/src/core/mission/missionOpenInEditor.ts

...adlock-extension/src/core/mission/missionUserChallenge.ts

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