Expose Candid init in .d.ts files

[peterpeterparker]

The init function generated by Candid IDL is handy when deploying a canister in JavaScript (whether for real deployments or during tests with picJS).

Currently, this function is not exposed in the .d.ts files of all packages in ic-js.

import type { IDL } from "@dfinity/candid";
export const idlFactory: IDL.InterfaceFactory;

This limitation can be overcome with a workaround:

// @ts-expect-error init is not packaged / exposed
import { idlFactory, init } from '@dfinity/ledger-icp/dist/candid/ledger.idl.js';

However, it would improve the developer experience to have it exposed directly.