Implement the X:Line commands

This PR implements the following commands:
- KLINE
- GLINE
- ZLINE
- ELINE
- QLINE

With the exception of server to server support (which I'll get on once this is reviewed) they are fully functional. I did run into a slight problem with the ZLINE command, where if a Z:Lined user connects, it disconnects them with a broken pipe rather than the actual ban reason. I'm not quite sure how to work around this issue.
The name for this should be ELINES.

Compare with the KLINES option from https://github.com/ircv3/ircv3-specifications/pull/28/files.