Auth: Add access token to in-proc communication and ServiceIdentity (#98926)

Use fake access token for in-proc grpc and add ServiceIdentity 
---------

Co-authored-by: gamab <gabriel.mabille@grafana.com>
Co-authored-by: Karl Persson <23356117+kalleep@users.noreply.github.com>

pkg/storage/unified/resource/client_test.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	claims "github.com/grafana/authlib/types"
 	"github.com/grafana/grafana/pkg/apimachinery/identity"
 )
 
@@ -16,11 +15,8 @@ func TestIDTokenExtractor(t *testing.T) {
 		assert.Error(t, err)
 		assert.Empty(t, token)
 	})
-	t.Run("should return an empty token for static requester of type service account as grafana admin ", func(t *testing.T) {
-		ctx := identity.WithRequester(context.Background(), &identity.StaticRequester{
-			Type:           claims.TypeServiceAccount,
-			IsGrafanaAdmin: true,
-		})
+	t.Run("should return an empty token when grafana identity is set", func(t *testing.T) {
+		ctx, _ := identity.WithServiceIdentitiy(context.Background(), 0)
 		token, err := idTokenExtractor(ctx)
 		assert.NoError(t, err)
 		assert.Empty(t, token)