Alerting: State manager to use InstanceStore (#53852)

* move saving the state to state manager when scheduler stops
* move saving state to ProcessEvalResults

* add GetRuleKey to State
* add LogContext to AlertRuleKey

pkg/services/ngalert/eval/testing.go

@@ -0,0 +1,74 @@
+package eval
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+
+	"github.com/grafana/grafana-plugin-sdk-go/data"
+
+	"github.com/grafana/grafana/pkg/services/ngalert/models"
+)
+
+type ResultMutator func(r *Result)
+
+func RandomState() State {
+	return []State{
+		Normal,
+		Alerting,
+		NoData,
+		Error,
+	}[rand.Intn(4)]
+}
+
+func GenerateResults(count int, generator func() Result) Results {
+	var result = make(Results, 0, count)
+	for i := 0; i < count; i++ {
+		result = append(result, generator())
+	}
+	return result
+}
+
+func ResultGen(mutators ...ResultMutator) func() Result {
+	return func() Result {
+		state := RandomState()
+		var err error
+		if state == Error {
+			err = fmt.Errorf("result_error")
+		}
+		result := Result{
+			Instance:           models.GenerateAlertLabels(rand.Intn(5)+1, "result_"),
+			State:              state,
+			Error:              err,
+			EvaluatedAt:        time.Time{},
+			EvaluationDuration: time.Duration(rand.Int63n(6)) * time.Second,
+			EvaluationString:   "",
+			Values:             nil,
+		}
+		for _, mutator := range mutators {
+			mutator(&result)
+		}
+		return result
+	}
+}
+
+func WithEvaluatedAt(time time.Time) ResultMutator {
+	return func(r *Result) {
+		r.EvaluatedAt = time
+	}
+}
+
+func WithState(state State) ResultMutator {
+	return func(r *Result) {
+		r.State = state
+		if state == Error {
+			r.Error = fmt.Errorf("with_state_error")
+		}
+	}
+}
+
+func WithLabels(labels data.Labels) ResultMutator {
+	return func(r *Result) {
+		r.Instance = labels
+	}
+}