Alerting: Move rule evaluation status logic out of prometheus API and into scheduler (#89141)

* Add health fields to rules and an aggregator method to the scheduler

* Move health, last error, and last eval time in together to minimize state processing

* Wire up a readonly scheduler to prom api

* Extract to exported function

* Use health in api_prometheus and fix up tests

* Rename health struct to status

* Fix tests one more time

* Several new tests

* Handle inactive rules

* Push state mapping into state manager

* rename to StatusReader

* Rectify cyclo complexity rebase

* Convert existing package local status implementation to models one

* fix tests

* undo RuleDefs rename

pkg/services/ngalert/api/testing.go

@@ -166,3 +166,29 @@ func (f fakeRuleAccessControlService) AuthorizeDatasourceAccessForRule(ctx conte
 func (f fakeRuleAccessControlService) AuthorizeDatasourceAccessForRuleGroup(ctx context.Context, user identity.Requester, rules models.RulesGroup) error {
 	return nil
 }
+
+type statesReader interface {
+	GetStatesForRuleUID(orgID int64, alertRuleUID string) []*state.State
+}
+
+type fakeSchedulerReader struct {
+	states statesReader
+}
+
+func newFakeSchedulerReader(t *testing.T) *fakeSchedulerReader {
+	return &fakeSchedulerReader{}
+}
+
+// setupStates allows the fake scheduler to return data consistent with states defined elsewhere.
+// This can be combined with fakeAlertInstanceManager, for instance.
+func (f *fakeSchedulerReader) setupStates(reader statesReader) *fakeSchedulerReader {
+	f.states = reader
+	return f
+}
+
+func (f *fakeSchedulerReader) Status(key models.AlertRuleKey) (models.RuleStatus, bool) {
+	if f.states == nil {
+		return models.RuleStatus{}, false
+	}
+	return state.StatesToRuleStatus(f.states.GetStatesForRuleUID(key.OrgID, key.UID)), true
+}