NodeJS bindings

[dgcoffman]

This PR adds NodeJS bindings with the following interface:

  loadTrustedSetup: (filePath: string) => SetupHandle;

  freeTrustedSetup: (setupHandle: SetupHandle) => void;

  blobToKzgCommitment: (blob: Blob, setupHandle: SetupHandle) => KZGCommitment;

  computeAggregateKzgProof: (
    blobs: Blob[],
    setupHandle: SetupHandle
  ) => KZGProof;

  verifyAggregateKzgProof: (
    blobs: Blob[],
    expectedKzgCommitments: KZGCommitment[],
    kzgAggregatedProof: KZGProof,
    setupHandle: SetupHandle
  ) => boolean;

  // Not used in 4844(?), not exported and not covered with test automation. But I think it probably works.
  verifyKzgProof: (
    polynomialKzg: KZGCommitment,
    z: BLSFieldElement,
    y: BLSFieldElement,
    kzgProof: KZGProof,
    setupHandle: SetupHandle
  ) => boolean;

I also added blst as a submodule.

Most of diff is a yarn lockfile.

Test instructions: README

[xrchz]

this copying is unfortunate - does passing blobs_param more directly not work? (like in the python version). not a big deal if you have to copy though.

[dgcoffman]

Agreed. I have tried a bunch of things but can't figure out anything other than memcpy.

blobs_param is of type Napi::Array. I've been googling and trying things. Nothing so far is working.

[xrchz]

Assuming the bindings actually build and work (I haven't tested) this looks great to me.