Add generic GetInto type converter for Get trait

[Doordashcon]

Description

Introduces GetInto<Inner, I, R>, a generic converter for the Get trait that leverages Into for type-safe conversions.

Issue

Currently, type conversions using the Get trait require manual implementation for each specific type pair (e.g., ConvertU16ToU32).

[kianenigma]

First thought of this alternative, but seeing how you use it in the downstream PR, I see that a struct is more useful https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=de287e5559e1e1d8bb79c9532ee2bfba

[bkchr]

@Doordashcon please format the code :)

[Doordashcon]

please review @kianenigma @bkchr

[bkchr]

Yeah not sure why you changed this?

[bkontur]

@Doordashcon Is this already accessible in polkadot-sdk? Maybe we could use it here: https://github.com/paritytech/polkadot-sdk/blob/master/substrate/frame/message-queue/src/lib.rs#L1720-L1727 instead of?

pub struct IntoU32<T, O>(core::marker::PhantomData<(T, O)>);
impl<T: Get<O>, O: Into<u32>> Get<u32> for IntoU32<T, O> {
	fn get() -> u32 {
		T::get().into()
	}
}

[bkchr]

@bkontur the linked struct is the reason this pr was created. We did not yet release the changes to crates.io. If you need them, go ahead and release a new version :)

[bkontur]

@bkontur the linked struct is the reason this pr was created. We did not yet release the changes to crates.io. If you need them, go ahead and release a new version :)

No, I don't need them. I was just reviewing Serban's PR for the message queue, and that IntoU32 reminded me of this GetInto PR

[bkchr]

Ahh no we added it for this pr, but yeah the idea is that we will use it in Polkadot sdk :)