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 client under both a temporary and a permanent ban gets the permanent one.
A request that makes a ban permanent gets permanently_banned. A ban rule, a
trap path or a CrowdSec decision gets the value for the ban it makes, 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

internal/discriminator/discriminator_test.go

@@ -639,7 +639,7 @@ func TestQuestionDeniedGetsTheBanResponse(t *testing.T) {
 			got := s.ask(client, "/")
 			wantDisposition(t, got, status, discriminator.DispositionDeny)
 			wantBody(t, got, http.StatusText(status)+"\n")
-			wantLine(t, s.out.requestLine(t), status, requestlog.ActionDenied)
+			wantLine(t, s.out.requestLine(t), status, requestlog.ActionClientDenied)
 		})
 	}
 }
@@ -655,8 +655,8 @@ func TestBanResponseCloseIsAnAnswerOfItsOwn(t *testing.T) {
 	wantDisposition(t, got, http.StatusOK, discriminator.DispositionClose)
 	wantBody(t, got, "")
 	// The visitor is sent nothing.
-	wantLine(t, s.out.requestLine(t), 0, requestlog.ActionDenied)
-	wantMetric(t, s.metrics(), `sww_requests_total{action="denied",instance="`+
+	wantLine(t, s.out.requestLine(t), 0, requestlog.ActionClientDenied)
+	wantMetric(t, s.metrics(), `sww_requests_total{action="client_denied",instance="`+
 		alertInstance+`",status_class="none"}`, 1)
 }
 
@@ -671,12 +671,12 @@ func TestBlockRuleIsDeniedWith403AndABanRuleWithTheBanResponse(t *testing.T) {
 	got := s.ask(client, "/blocked")
 	wantDisposition(t, got, http.StatusForbidden, discriminator.DispositionDeny)
 	wantLine(t, s.out.requestLine(t), http.StatusForbidden,
-		requestlog.ActionRuleBlocked)
+		requestlog.ActionBlockedByBlockRule)
 
 	got = s.ask(client, "/.env")
 	wantDisposition(t, got, http.StatusTooManyRequests, discriminator.DispositionDeny)
 	wantLine(t, s.out.requestLines(t, 2)[1], http.StatusTooManyRequests,
-		requestlog.ActionBanned)
+		requestlog.ActionTemporarilyBanned)
 }
 
 func TestQuestionUnderTheOwnPrefixIsDeniedWith404AfterTheChecks(t *testing.T) {
@@ -709,7 +709,7 @@ func TestObserveModeAllowsAndLogsWhatEnforceModeWouldHaveDone(t *testing.T) {
 
 	line := s.out.requestLine(t)
 	wantLine(t, line, http.StatusOK, requestlog.ActionForward)
-	wantWouldAction(t, line, requestlog.ActionDenied)
+	wantWouldAction(t, line, requestlog.ActionClientDenied)
 }
 
 func TestObserveModeRefusalAnsweredAllowCountsForTheErrorBurst(t *testing.T) {
@@ -894,7 +894,7 @@ func TestDeniedRequestIsFinishedAtItsDecision(t *testing.T) {
 		t.Errorf("history is %+v, want the refused request alone", history)
 	}
 
-	const series = `sww_requests_total{action="rate_limited",instance="` +
+	const series = `sww_requests_total{action="client_is_rate_limited",instance="` +
 		alertInstance + `",status_class="4xx"}`
 
 	wantMetric(t, s.metrics(), series, 1)
@@ -1298,11 +1298,11 @@ func TestEveryDeniedRequestsReportGetsItsLastLine(t *testing.T) {
 	}{
 		{
 			"deny", map[string]string{denyNets: client}, "/", http.StatusForbidden,
-			requestlog.ActionDenied,
+			requestlog.ActionClientDenied,
 		},
 		{
 			"close", map[string]string{denyNets: client, banResponse: banResponseClose}, "/",
-			0, requestlog.ActionDenied,
+			0, requestlog.ActionClientDenied,
 		},
 		{"own prefix", nil, discriminator.HealthPath, http.StatusNotFound,
 			requestlog.ActionAdmin},