BotServ BADWORDS: user-configurable regex kicker

BADWORDS <#channel> ADD|DEL|LIST|CLEAR manages a channel's badword
patterns, each a regular expression, so a channel matches whatever it
wants — an improvement over Anope's fixed ANY/SINGLE/START/END. Enable
with KICK <#channel> BADWORDS ON.

Uses the regex crate: it's finite-automata based with linear-time
matching, so untrusted user patterns can't cause catastrophic
backtracking (ReDoS). A channel's patterns compile into one RegexSet
(single-pass match against all of them), cached in the engine and rebuilt
only when the list's revision changes — so the hot path is one is_match
call, no per-message compilation or allocation. Patterns are validated
(and size-limited) at add time; matching is case-insensitive by default.

src/grpc.rs

@@ -138,6 +138,7 @@ fn to_wire(entry: &LogEntry) -> Option<ReplicationEvent> {
         | Event::ChannelEntryMsgSet { .. }
         | Event::ChannelSettingsSet { .. }
         | Event::ChannelKickerSet { .. }
+        | Event::ChannelBadwordsSet { .. }
         | Event::ChannelTopicSet { .. }
         | Event::ChannelSuspended { .. }
         | Event::ChannelUnsuspended { .. }