Live: check schema equality between push messages (#34548) (#34801)

(cherry picked from commit 67028af99e)

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

pkg/tsdb/testdatasource/csv_data_test.go

@@ -70,9 +70,8 @@ func TestReadCSV(t *testing.T) {
 	require.NoError(t, err)
 
 	frame := data.NewFrame("", fBool, fBool2, fNum, fStr)
-	frameToJSON, err := data.FrameToJSON(frame)
+	out, err := data.FrameToJSON(frame, data.IncludeAll)
 	require.NoError(t, err)
-	out := frameToJSON.Bytes(data.IncludeAll)
 
 	require.JSONEq(t, `{"schema":{
 		"fields":[