Add support for SHA3

[rkeene]

SHA3 is becoming more popular and supported by NodeJS, support for it should be added here as well. The popular package "jsSHA" supports this in a relatively easy to wrap way:

class browserSHA3_256 {
	#obj;

	constructor(hmacKey = undefined) {
		if (hmacKey === undefined) {
			this.#obj = new jssha("SHA3-256", "ARRAYBUFFER");
		} else {
			if (!(hmacKey instanceof Uint8Array)) {
				throw(new Error('only support Uint8Array for HMAC Key'));
			}

			this.#obj = new jssha("SHA3-256", "ARRAYBUFFER", {
				hmacKey: {
					format: "UINT8ARRAY",
					value: hmacKey
				}
			});
		}
	}

	update(data, options = undefined) {
		if (options !== undefined) {
			throw(new Error('options for "update" not supported'));
		}

		if (!(data instanceof ArrayBuffer)) {
			data = bufferToArrayBuffer(Buffer.from(data));
		}

		this.#obj.update(data);

		return(this);
	}

	digest(encoding = undefined) {
		let retval;
		switch (encoding) {
			case 'hex':
				retval = this.#obj.getHash("HEX");
				break;
			case undefined:
				retval = Buffer.from(this.#obj.getHash("ARRAYBUFFER"));
				break;
			default:
				throw(new Error(`unsupported encoding "${encoding}"`));
		}

		return(retval);
	}
}