feat: Add NitroModules.box(...) to support using Nitro Modules from any Runtime/Worklets context

[mrousavy]

While Nitro is runtime-agnostic and all HybridObjects can be used from a any Runtime, some threading/worklet libraries (like react-native-worklets-core) do not yet support copying over HybridObjects as they use newer JSI APIs like jsi::NativeState.

While those APIs are not yet available in react-native-worklets-core, you can still use every Nitro Hybrid Object in a separate Runtime/Worklet context by just boxing it yourself:

const something = NitroModules.createHybridObject<Something>('Something')
const boxed = NitroModules.box(something)
const context = Worklets.createContext('DummyContext')
context.runAsync(() => {
  'worklet'
  const unboxed = boxed.unbox()
  console.log(unboxed.name) // --> "Something"
})

The BoxedHybridObject<T> is implemented as a jsi::HostObject, which can be used from any runtime.

This is slower than just efficiently copying over the jsi::NativeState (plus it's prototype chain), so we'll work on implementing a truly native and automatic solution next - cc @hannojg @chrfalch.