feat(workspace): Add Nix Shell build environment

[vpochapuis]

What

This is a proposition of a Nix Shell ready to build and use the project with.
Feedback, improvements and modifications would be great!

Tested:

• x86 Native Build and Run
• WASM Build Serve and Run with Trunk
• Android release (Wont work due to missing custom xbuild, this could be added using the Nix rustPlatform.buildRustPackage however would be easier to have the Cargo.lock present in the xbuild repo for it).
• iOS release (I am not sure yet how this works)

Why

Let users quickly setup a working build environment in a distro/OS agnostic way. (This also could be used for CI use! However for binary release might need to use the patchelf utility).

How

I tried to bundle all I could find from the repository apart from some target CI release tools that would need further help to integrate.

(if possible, preference for a git squash merge using PR name or other, as the commit descriptions in my current PR state aren't great)

[NiklasEi]

Just in case you didn't see it: #85 is a previous attempt.
Why do we need to use nightly for everything?

[vpochapuis]

Just in case you didn't see it: #85 is a previous attempt. Why do we need to use nightly for everything?

Thank you for your quick feedback!

Indeed there is no need to use nightly for everything I think i set it when trying to build xbuild and the android part. I will remove it.

As for #85 it seems this PR hasn't been updated for a while, I would like to give another chance to try and introduce this feature to the repository~