feat: add notification policy and password change message (#5065)

Implementation of new notification policy with functionality to send email when a password is changed

internal/command/policy_notification_model.go

@@ -0,0 +1,31 @@
+package command
+
+import (
+	"github.com/zitadel/zitadel/internal/domain"
+	"github.com/zitadel/zitadel/internal/eventstore"
+	"github.com/zitadel/zitadel/internal/repository/policy"
+)
+
+type NotificationPolicyWriteModel struct {
+	eventstore.WriteModel
+
+	PasswordChange bool
+	State          domain.PolicyState
+}
+
+func (wm *NotificationPolicyWriteModel) Reduce() error {
+	for _, event := range wm.Events {
+		switch e := event.(type) {
+		case *policy.NotificationPolicyAddedEvent:
+			wm.PasswordChange = e.PasswordChange
+			wm.State = domain.PolicyStateActive
+		case *policy.NotificationPolicyChangedEvent:
+			if e.PasswordChange != nil {
+				wm.PasswordChange = *e.PasswordChange
+			}
+		case *policy.NotificationPolicyRemovedEvent:
+			wm.State = domain.PolicyStateRemoved
+		}
+	}
+	return wm.WriteModel.Reduce()
+}