Feat: Introduce Inertia version 2 DeferredProp feature

[Attakay78]

Why this PR:

• This PR adds supports for Inertia.js DeferredProp feature in the version 2 update. This allows data to be deferred and loaded later via a subsequent request after user initiated request.
• Adds supports for partial reloads to be asynchronous as supported by inertia.js version 2.

[Attakay78]

@hxjo I have raised a WIP RP which works, I will resolve the failing tests and type check later.

Would you like us to update the existing vue backend and frontend example with the version 2 changes or have a dedicated example for that?

Also I have added async support for partial loading.

[hxjo]

@Attakay78 a few points:

1. For now, please add docstrings on new functions, new utils that those are internal only.
2. Do not bump the version of the package with a major. Given all required changes to support inertia 2 have not been implemented, there's no point in exposing those for now.
3. For now, please add the examples in a subfolder indeed, as those are not to be used for now

Thanks for the work !!

[Attakay78]

@hxjo Can you review the implementations so far.

[Attakay78]

@hxjo Comments addressed

[hxjo]

@Attakay78 could you keep the git history, rather than force-pushing and erasing the log of changes ?
That makes it hard to follow the chain of thoughts. It's also very unpractical for reviews.
I'll take another look at the PR on my lunch break and I'll probably approve and merge it

[Attakay78]

@hxjo Noted, normally do that when I don't want to have too many commits on one PR. Going forward, I will push a new commit for major or important changes and still do the force for trivial issues to prevent too many commits.

[Attakay78]

@hxjo Can we get this done. Working on the second feature.