servewaf always answers rproxy well within its time limit (closes #182)

A question waits on GeoJS at most 800ms, the new default of
SWWAF_LOOKUP_TIMEOUT. In enforce mode it does not wait at all when it is
over the header limits, on a fetched blocklist with deny, on the CrowdSec
decision list, or over a whole rate limit. Not waiting never lowers a
client's limit. Just before the Core Rule Set, servewaf refuses more than
50 cookies or 100 header fields with 431.

Shared default changed: SWWAF_LOOKUP_TIMEOUT also applies to smallwebwaf
with no command.
Judgement call: SWWAF_REPUTATION_TIMEOUT stays 2s, since no request waits
on the DNS blocklists or AbuseIPDB.

Model: opus-5-5

internal/requestlog/requestlog.go

@@ -18,7 +18,8 @@ import (
 const (
 	// ActionForward is a request passed to the app.
 	ActionForward = "forward"
-	// ActionTooLarge is a request or response over its size limit.
+	// ActionTooLarge is a request or response over its size limit, or, in
+	// servewaf, a request over the header limits.
 	ActionTooLarge = "too_large"
 	// ActionTimedOut is a request or response that ran out of time.
 	ActionTimedOut = "timed_out"
@@ -139,7 +140,8 @@ type Line struct {
 	// WouldAction is, in observe mode, the action enforce mode would have
 	// taken with a request it would have refused: ActionDenied,
 	// ActionBanned, ActionCountryDenied, ActionRateLimited,
-	// ActionRuleBlocked or ActionWAFBlocked.
+	// ActionRuleBlocked, ActionWAFBlocked, or, in servewaf, ActionTooLarge
+	// for the header limits.
 	WouldAction string `json:"would_action,omitempty"`
 	// LimitPercent and LimitPercentSetting are, for a request the rate
 	// limits counted whose client a biased threshold gives a percentage of