fetch - zstd support

[KhafraDev]

Relies on nodejs/node#48412

[KhafraDev]

https://github.com/web-platform-tests/wpt/tree/master/fetch/content-encoding/zstd

[RomkaLTU]

Removing for now zstd from accept-encoding headers:

'accept-encoding': 'gzip, deflate, br',

Took me some time to realize this is an encoding issue. I thought I was crazy.

[J3m5]

Zstandard support has landed in Node 23.8.0
https://nodejs.org/en/blog/release/v23.8.0#support-for-the-zstd-compression-algorithm
nodejs/node#52100

[J3m5]

It is now supported in Node 22.15.0
https://github.com/nodejs/node/releases/tag/v22.15.0

[mcollina]

@J3m5 would you like to send a PR?

[J3m5]

Hi @mcollina,
I've just opened this PR.
Please let me know if anything is missing or needs to be adjusted.