Add copying IntoIter implementation

[Gaspard--]

Apologies if any terms aren't right, I'm still learning rust.

Currently, if you want to return an iterator consuming a temporary variable, you can't, because IntoIter is only implemented for &T and &mut T.

    // Works, because arrays implement IntoIter returning f32
    for x in (|| [0.0f32, 1.0f32].into_iter())() {
        print!("{}\n", x);
    }
    // Does not work, because nalgebra::Vector2 does not implement IntoIter returning f32, so the compiler picks &f32 instead
    for x in (|| Vector2::new(0.0f32, 1.0f32).into_iter())() {
        print!("{}\n", x);
    }

https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=e3c5472e96dbe560be70cf3c5e55c6b8

I was wondering if would possible to add the missing to implementation to support this? Is there some potential technical limitation I can't see?

Note that it's currently possible to work around this problem for very simple situations by chaining iterators over copies of each field.