feat(http): add zstd support

* feat(http): add zstd support through a reqwest feature flag

Author: tedbyron

Cargo.lock

@@ -68,6 +68,7 @@ cookies = ["reqwest/cookies", "dep:cookie_store", "dep:bytes"]
 gzip = ["reqwest/gzip"]
 brotli = ["reqwest/brotli"]
 deflate = ["reqwest/deflate"]
+zstd = ["reqwest/zstd"]
 trust-dns = ["reqwest/trust-dns"]
 socks = ["reqwest/socks"]
 http2 = ["reqwest/http2"]