feat: add renderHook function

[pierrezimmermannbam]

Summary

This pr provides a basic implementation of renderHook as requested in #869. The solution is almost a copy past from the one made in react testing library

Test plan

Some test cases were added, also inspired from the implementation from react testing library

[AugustinLF]

The @testing-library/react PR still hasn't been merged, so I'd like for it to be merged first before getting that in. I'm monitoring said PR, but don't hesitate to ping me once it's merged if I miss it.

[mpeyper]

The RTL PR has been merged now. Please let me know if there is anything I can do to progress this.

[AugustinLF]

Implementation and tests look correct to me. Could you fix the conflicts and also add documentation for it please?

https://github.com/callstack/react-native-testing-library/blob/main/website/docs/API.md

After that I think we should be able to get that in!

[pierrezimmermannbam]

I'm working on migrating to typescript, I'll add documentation afterwards, it shouldn't take long

[pierrezimmermannbam]

It's done, there is a typing issue because the option param is optional so initialProps may not be defined when it needs to be but changing the typing would mean having a different api from the one of react-hooks-testing-library and I'm not sure it's something we want.

I also added documentation, I used the documentation I found on the react-hooks-testing-library repo and added some examples

[AugustinLF]

Oops forgot to ask for flow types https://github.com/callstack/react-native-testing-library/blob/main/typings/index.flow.js But after that we should be good I believe

[pierrezimmermannbam]

@AugustinLF I added the flow types

[thymikee]

Pushed some documentation updates. Looks pretty!