request: automatic dehoist

[kyranet]

Is your feature request related to a problem? Please describe.

Many members join a server with an hoisted username.

Describe the solution you'd like

Skyra should support automatic de-hoisting when a member joins the server. This might need to take #2200 into account to not run into nickname conflicts.

Describe alternatives you've considered

N/a

Additional context

#222 in #suggestions