[3.x] Revert HTTPRequest gzip compression support.

[Faless]

Partial revert of commit c1135cf.

See: #48651 (comment)

#48651 causes a few regressions including #53085 so it needs to be reverted. The original PR on master #38944 is left for now but will need work if we want to keep in 4.0 (or will need revert too).

Issues:

• Some platform/HTTPClient might not allow those headers (HTML5)
• Response is not decompressed when saved to file.
• We need facilities to decompress a stream (i.e. not decompress all in memory but in chunks to file).

I've left the changes adding request_raw and Compression::decompress_dynamic since they are both still needed anyway (and for now will allow to implement manual gzip decompression in 3.x).

[akien-mga]

Thanks!