Add support for zstd (Zstandard) encoding

[gaby]

Hello, currently fasthttp supports gzip and brotli as encoding when serving compressed content. It also supports them for fasthttp.fs. It would be very beneficial to add support for zstd whicb provides faster decompression rates.

The library used by fashttp already supports zstd. Information here: https://github.com/klauspost/compress/tree/master/zstd#zstd

Tools like curl already support auto-decompression of zstd content since 2020: https://daniel.haxx.se/blog/2020/08/19/curl-7-72-0-more-compression/

[v4rn]

@erikdubbelboer new here. can i pick this?

[erikdubbelboer]

@v4rn yes please!

[gaby]

@v4rn You had any luck with this?

[v4rn]

@gaby sorry, I had some competing priorities last couple of weeks, just started looking at this. Prioritizing it this week.

[gaby]

@v4rn Any luck? thanks!

[gaby]

@v4rn Any update on this?

[Max-Cheng]

@gaby Since I'm curious about the internal implementation of fiber, I'm going to start fasthttp from this issue, wish me luck!

[gaby]

@Max-Cheng Awesome, yeah main reason i opened this ticket is to eventually add support in Fiber.

[Max-Cheng]

@gaby zstd will be soon. I need more time to test corner cases
#1700

[gaby]

@Max-Cheng Awesome! Looking forward

[gaby]

Fixed via #1701