registerLabel should allow more parameters or have attributes

Case 1: User should have ability to put laber not only as an string
``` java
TLRPC.User user = (TLRPC.User) object;
ApplicationLoader.behaiv().registerLabel(user.username);
```
Case 2: Probably user can put multiple keys into label or have attributes method
``` java
TLRPC.User user = (TLRPC.User) object;
ApplicationLoader.behaiv().registerLabel(user.id, user.username);
```