Drop the `isStream` option

[szmarczak]

got.stream(...) should be the only way to make typings easier

[szmarczak]

We also should drop responseType and resolveBodyOnly as those change the return type as well.

[sindresorhus]

We also should drop responseType and resolveBodyOnly as those change the return type as well.

Probably not doing this for now as it's a much bigger breaking change.