Anon: Small fixes to anon service structure (#79566)

* add ListDevices to service

* improve fake

* fix missing cfg field

* cannot be unexported

pkg/services/anonymous/anontest/fake.go

@@ -6,10 +6,12 @@ import (
 	"time"
 
 	"github.com/grafana/grafana/pkg/services/anonymous"
+	"github.com/grafana/grafana/pkg/services/anonymous/anonimpl/anonstore"
 )
 
 type FakeService struct {
 	ExpectedCountDevices int64
+	ExpectedListDevices  []*anonstore.Device
 	ExpectedError        error
 }
 
@@ -17,13 +19,14 @@ func NewFakeService() *FakeService {
 	return &FakeService{}
 }
 
-type FakeAnonymousSessionService struct {
-}
-
 func (f *FakeService) TagDevice(ctx context.Context, httpReq *http.Request, kind anonymous.DeviceKind) error {
-	return nil
+	return f.ExpectedError
 }
 
 func (f *FakeService) CountDevices(ctx context.Context, from time.Time, to time.Time) (int64, error) {
-	return f.ExpectedCountDevices, nil
+	return f.ExpectedCountDevices, f.ExpectedError
+}
+
+func (f *FakeService) ListDevices(ctx context.Context, from *time.Time, to *time.Time) ([]*anonstore.Device, error) {
+	return f.ExpectedListDevices, f.ExpectedError
 }