This PR changes Node.js/npm compatibility layer to use polyfills for
built-in Node.js
embedded in the snapshot (that are coming from "ext/node" extension).
As a result loading `std/node`, either from
"https://deno.land/std@<latest>/" or
from "DENO_NODE_COMPAT_URL" env variable were removed. All code that is
imported via "npm:" specifiers now uses code embedded in the snapshot.
Several fixes were applied to various modules in "ext/node" to make
tests pass.
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Co-authored-by: Yoshiya Hinosawa <stibium121@gmail.com>
Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>
