This PR fixes error handling in Servo's HTTP fetch implementations to
properly handle content decompression failures (e.g., bad gzip content)
by treating them as network errors as defined in WPT.
- Fixed some previously failing tests in bad-gzip-body.any.js that now
properly reject when consuming bodies with bad gzip content
- Several fetch metadata tests now pass correctly
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Signed-off-by: araya <araya@araya.dev>