NUTCH-3139 protocol-okhttp: add support for zstd content-encoding

[sebastian-nagel]

• upgrade to OkHttp 5.3.2
• enable support for zstd content-encoding

Meta sites already support zstd content-encoding:

$> $NUTCH_HOME/bin/nutch parsechecker https://www.llama.com/faq/
...
  _request_ = GET /faq/ HTTP/2
...
Accept-Encoding: zstd, br, gzip
...
  _response.headers_ = HTTP/2 200 
vary: Accept-Encoding
content-encoding: zstd
...

(with http.useHttp2, store.http.request and store.http.headers set to true)

[lewismc]

Very nice. Also good to get a major dependency upgrade for the okhttp dependency.