[Feature]: EasyAuth integration

### 🚀 Description

[EasyAuth](https://github.com/NikitaCartes/EasyAuth) allows access with both online and offline accounts. But when using an offline account with a username that is already registered in Mojang we get `Invalid session` error instead of verification prompt. To support it we probably need to:
- Prioritize verification message over invalid session message,
- Execute `/auth markAsOffline ` after successful verification of offline account (sdlink should detect if account is offline and register it with EasyAuth)

### 💡 Use Case

We often use offline account for bots on our server. It is convenient to name a bot after a farm it is used on (e.g. `Slime` for slime farm, `Iron` for iron etc.). But these simple names are often taken by existing online accounts. Jumping through the hoops of manually marking them is annoying. Since we would need to verify them anyway, marking at this point would make it much easier.