app/vmalert: adopt additional rule states in the list rules API

In grafana, the alert list panel can use VictoriaMetrics as datasource
and call `/api/v1/rules` api with [specific
states](https://grafana.com/docs/grafana/latest/alerting/fundamentals/alert-rule-evaluation/nodata-and-error-states/#alert-instance-states).
See
https://play-grafana.victoriametrics.com/d/febljk0a32qyoa/3e68cf3?orgId=1&from=now-1h&to=now&timezone=browser&var-prometheus_datasource=P4169E866C3094E38&var-jaeger_datasource=P14D5514F5CCC0D1C&var-victorialogs_datasource=PD775F2863313E6C7&var-service_namespace=$__all&var-service_name=checkout&refresh=5m&editPanel=40.
Some states are already defined in vmalert, although with different
names. Others, such as "recovering", are currently undefined.
This pull request adopts all these states, rather than fail the request.

Above panel request also uses the `matcher` param to filter rules.
However,
[prometheus](https://prometheus.io/docs/prometheus/latest/querying/api/#rules)
also does not support this parameter and simply ignore it, so I don't
think vmalert needs to support it now.

JFYI, the grafana [Alerting
page](https://play-grafana.victoriametrics.com/alerting) does not
include any of the mentioned `state` or `matcher` parameters in rule
listing requests to the datasource. Filtering is handled by the Grafana
frontend, so most users are not affected by partial support for
filtering in backend products.

Related PR https://github.com/VictoriaMetrics/VictoriaMetrics/pull/10778

app/vmalert/web.go

@@ -52,7 +52,13 @@ var (
 		"alert":  rule.TypeAlerting,
 		"record": rule.TypeRecording,
 	}
-	ruleStates = []string{"ok", "nomatch", "inactive", "firing", "pending", "unhealthy"}
+
+	// The "recovering", "noData", "normal", "error" states are used by Grafana.
+	// Ignore "recovering" since it is not currently acknowledged by vmalert,
+	// treat "noData" as an alias for "nomatch",
+	// treat "normal" as an alias for "inactive",
+	// treat "error" as an alias for "unhealthy"
+	ruleStates = []string{"ok", "nomatch", "inactive", "firing", "pending", "unhealthy", "recovering", "noData", "normal", "error"}
 )
 
 type requestHandler struct {
@@ -363,6 +369,15 @@ func newRulesFilter(r *http.Request) (*rulesFilter, *httpserver.ErrorWithStatusC
 			if !slices.Contains(ruleStates, v) {
 				return nil, errResponse(fmt.Errorf(`invalid parameter "state": contains not supported value %q`, v), http.StatusBadRequest)
 			}
+			// Replace grafana states with supported internal states
+			switch v {
+			case "noData":
+				v = "nomatch"
+			case "normal":
+				v = "inactive"
+			case "error":
+				v = "unhealthy"
+			}
 			rf.states = append(rf.states, v)
 		}
 	}