Immutable payloads #27
Description
To help users of RxBeach ensure functional style in their streams, it would be nice to have the payloads be completely immutable, by both recursively defining them as readonly and protecting them with Object.freeze and/or Object.defineProperty(... writable: false}).
This issue is a successor of #21, and already implemented in #25, but is blocked by implementation cost in Ardoq front.