Name request log actions so they say what they mean (closes #229)

Rename too_large, rate_limited, rule_blocked and denied, and split banned
into temporarily_banned and permanently_banned by whether the ban runs out.
A request that makes a ban permanent gets permanently_banned. A ban the
request itself makes gets the value for that ban, and in observe mode
would_action names the ban enforce mode would have made.

The offence kind rule_blocked follows, as a metric label and a key in
clients.json.

Model: opus-5-5

docs/state-files.md

@@ -63,8 +63,9 @@ since it was first seen:
 - total requests, and how many were forwarded and how many refused;
 - body bytes of its requests, and of the responses it was sent;
 - responses by status class;
-- offences by kind: `limit`, `attack`, `rule_blocked` and `waf_blocked`. A file
-  may also hold `token_refused`, which is kept, and which nothing adds to.
+- offences by kind: `limit`, `attack`, `blocked_by_block_rule` and
+  `waf_blocked`. A file may also hold `token_refused`, which is kept, and which
+  nothing adds to.
 
 ## `lookups.json`