Move _http_* to be internal APIs.

[bjohansebas]

I’d like to know if it’s a good idea to move _http_* to be internal APIs and start deprecating them, as was done in https://github.com/nodejs/node/blob/main/lib/_tls_common.js.

cc: @nodejs/http

[mcollina]

yes

[mcollina]

yes