Support for prefixing messages [FEATURE]

[Rustbread]

Is your feature request related to a problem? Please describe.
Mod works quite well but it would be nice to have a tab that we would write message and it would be whispered to preset target.

Describe the solution you'd like
While configuring Tab ability to set Prefix to all messages send through this tab, for example we crate Jake DM tab and set Prefix to /w Jake when we write Test in this tab we would actually send /w Jake Test thus whispering this message without the need to use /w Jake again and again.

Having custom Prefix would make the solution generalized, we could make it work which FTBTeams msg for example.