get TextEncoder/TextDecoder from JSM so 'length' defined on array from buffer of array from TextEncoder
(cherry picked from commit ced72ebdeeb2e743c73599e177101a721aa54734)
when redefining TextEncoder/TextDecoder, don't reimport Services symbol
(cherry picked from commit f7adcd210534612601ce6aac1a177f33e4ff99b1)