feat: impl From<Infallible> for ErrorObject

[niklasad1]

This is useful for users that are providing something similar to Infallible for rpcs that returns Infallible.

#[rpc(server, client)]
pub trait Rpc
{
	#[method(name = "say_something)]
	async fn say_something(&self) -> Result<String, Infallible>;
}

[Copilot]

Pull Request Overview

This PR adds a conversion implementation from Infallible to ErrorObject, enabling users to work with RPCs that return Infallible.

• Introduces an import for Infallible in error.rs
• Implements From for ErrorObject using an unreachable match