feat(i18n): Implement localization

[kdev]

🔖 Feature description

Discord introduced localization for /-Commands and their interactions (see Localized Responses and /-Command localization).

We should also implement this as it is a long-time goal for us to create some kind of localized bot (since the last "Dispatcher")

✔️ Solution

### Tasks
- [ ] Implement "localized responses" and "/-Command localization" as descriped above
- [ ] use `i18next` for localization