Public rust crate for Parcel API and moving napi bindings to node_bindings

[alshdavid]

In this PR I move the napi bindings out of the parcel_core package, the idea is the parcel_core package will be agnostic to the caller context where context specific behaviour would be consumed by the core abstracted behind traits (like Resolver, etc).

Test instructions

yarn build-native-release

[alshdavid]

So the idea is:

cargo add parcel_core

Which is eventually used something like

use parcel_core::Parcel;
use parcel_core::ParcelOptions;
use parcel_core::ParcelRunOptions;

fn main() {
  let parcel = Parcel::new(ParcelOptions { /* ... */ });

  let report = parcel.run(ParcelRunOptions {  /* ... */  });
  println!("{:#?}", report);
}

For Napi bindings:

use parcel_core::Parcel;
use parcel_core::ParcelOptions;
use parcel_core::ParcelRunOptions;
use parcel_napi::ParcelNapiConnector;

#[napi]
fn main() {
  let parcel_napi = ParcelNapiConnector::new();
  // napi glue code

  let parcel = Parcel::new(ParcelOptions { 
    plugin_connectors: vec![parcel_napi],
  });

  let report = parcel.run(ParcelRunOptions {  /* ... */  });
  println!("{:#?}", report);
}