Support more ELIST types

[DanielOaks]

Right now we support doing a LIST with the time stuff, but not much else. Take a look at the Modern list and support more of dis.

Links:

https://modern.ircdocs.horse/#elist-parameter
https://github.com/ergochat/ergo/blob/0baaf0/irc/config.go#L1576
https://github.com/ergochat/ergo/blob/55cf1e/irc/server.go#L1042
https://github.com/ergochat/ergo/blob/9b6ec0/irc/handlers.go#L1640

[DanielOaks]

https://modern.ircdocs.horse/#elist-parameter
https://github.com/oragono/oragono/blob/c1d4c55/irc/handlers.go#L1410
https://github.com/oragono/oragono/blob/c1d4c55/irc/server.go#L945

[slingamn]

Someone asked about this today, so let's try and finally get it into 2.9 :-)