Add an op to list the network interfaces on the system.
Prep work for #8137 and `os.networkInterfaces()` Node compat in std.
Refs denoland/deno_std#1436.
Fixes "op_set_exit_code" by sharing a single "Arc" between
all workers (via "op state") instead of having a "global" value stored in
"deno_runtime" crate. As a consequence setting an exit code is always
scoped to a tree of workers, instead of being overridable if there are
multiple worker tree (like in "deno test --jobs" subcommand).
Refactored "cli/main.rs" functions to return "Result<i32, AnyError>" instead
of "Result<(), AnyError>" so they can return exit code.
Set the exit code to use if none is provided to Deno.exit(), or when
Deno exits naturally.
Needed for process.exitCode Node compat. Paves the way for #12888.
This commit moves Deno JS runtime, ops, permissions and
inspector implementation to new "deno_runtime" crate located
in "runtime/" directory.
Details in "runtime/README.md".
Co-authored-by: Ryan Dahl <ry@tinyclouds.org>