Add support for SHA3

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:

```js
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);
}
}
```