React 19: add support for useEffectEvent hook

[shsr04]

This MR provides support for the new React 19 hook useEffectEvent.

This is a useful hook when you want to ignore "non-reactive" callbacks from effect dependencies.

After some npm dependency hacking, I got it to work locally and also added a unit test.

Note the particular design of useEffectEvent, which I have reproduced in this implementation:

Effect Event functions do not have a stable identity. Their identity intentionally changes on every render.

Let me know what you think 😎