zlib-ng
We only want one zlib dependency. Zlib dependencies are reorganized so they use a hidden `__vendored_zlib_ng` flag in cli that enables zlib-ng for both libz-sys (used by ext/node) and flate2 (used by deno_web).
Move all op related code of "ext/node" to "ext/node/ops" module. These files were unnecessarily scattered around the extension.