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/proxy/lookup_test.go

@@ -319,7 +319,7 @@ func TestLookupHeadersArePassedToTheAppAndTheClientsOwnRemoved(t *testing.T) {
 	addr, out, _ := startProxyWithClock(t, app.URL, geojsURL, time.Now, map[string]string{
 		trustedProxies:   trustLocalhost,
 		lookupTimeout:    "1h",
-		addLookupHeaders: "true",
+		addLookupHeaders: on,
 	})
 	s := &sender{t: t, addr: addr, out: out}
 
@@ -383,8 +383,8 @@ func TestRequestWaitsAsLongAsTheLookupTimeoutSays(t *testing.T) {
 	// network, which would keep that clock from moving on: the request is
 	// handed to the proxy's handler, and GeoJS is one that never answers.
 	synctest.Test(t, func(t *testing.T) {
-		// Not the default second. The exclusive list needs the answer, and
-		// the app is never reached.
+		// Not the default. The exclusive list needs the answer, and the app
+		// is never reached.
 		const timeout = 3 * time.Second
 
 		server, out, _ := newProxy(t, "http://app.invalid", unansweredGeoJSURL,