[Replay] Read response body stream instead of `body.text()`

Currently, we use await body.text() to get the response body of a fetch request for replay, both to get the body content as well as to calculate the length of the body.

This has the problem that if the body is a continuous stream, this will never (or very late) resolve. We kind-of solved this recently at least insofar as that we abort after 500ms, but since we still called await body.text() before we'll continue to read from the stream, even if we are discarding it.

We should look into reading the stream manually instead of using body.text(), which would unlock us being able to stop reading it after some time. But this means we need to take care of text conversion in there ourselves.

Related to https://github.com/getsentry/sentry-javascript/issues/9616

Comece rastreando o tratamento de respostas fetch no Replay, que atualmente chama body.text(), e leia a issue relacionada 9616 para obter contexto. Verifique se o stream da resposta pode ser lido manualmente com conversão para texto e cálculo do comprimento, permitindo que streams contínuos parem após o timeout sem continuar consumindo o body.