feat: polyfill missing things

[grabbou]

There are certain things that this package requires to work:

• TextDecoder
• Streams
• Async Iterators

They are not available in RN at the moment.

https://github.com/callstackincubator/react-native-fast-ws/blob/2a8a04048ed1e841e68df590157fed2f6d327f67/example/index.js#L1-L4

We should create a package or an entry-point that bings all these polyfills automatically, so that users don't have to do it manually.