Add Bot selection for Slash Command Autocomplete

[Luc1412]

Description

When just typing / in the chat window all commands appear with a bot selection on the left.

When typing a command this selection disappears and just commands (sorted by popularity?) appear.

Although there are other bots with a settings command. While typing, all matching commands from all bots should be displayed (the bot picker should stay).

Why This is Needed

This decreases the discoverability of the "hidden" bots.