Auth: Refactor auth package (#58920)

* Auth: move interface to its own file

* Auth: move to test package

* Auth: move quota consts to auth file

* Auth: move service to impl package

* Auth: move interfaces and related models to auth package

* Auth: Create sub package and type alias to avoid circular dependency

pkg/middleware/quota_test.go

@@ -6,7 +6,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/auth"
 	"github.com/grafana/grafana/pkg/services/quota/quotatest"
 	"github.com/grafana/grafana/pkg/services/user"
 	"github.com/grafana/grafana/pkg/setting"
@@ -55,8 +55,8 @@ func TestMiddlewareQuota(t *testing.T) {
 		setUp := func(sc *scenarioContext) {
 			sc.withTokenSessionCookie("token")
 			sc.userService.ExpectedSignedInUser = &user.SignedInUser{UserID: 12}
-			sc.userAuthTokenService.LookupTokenProvider = func(ctx context.Context, unhashedToken string) (*models.UserToken, error) {
-				return &models.UserToken{
+			sc.userAuthTokenService.LookupTokenProvider = func(ctx context.Context, unhashedToken string) (*auth.UserToken, error) {
+				return &auth.UserToken{
 					UserId:        12,
 					UnhashedToken: "",
 				}, nil