/// Used to do reference-to-value conversions thus not consuming the input value.
///
/// This is mainly used with [`Context`] to extract "subcontexts" from a reference to main application
/// state.
///
/// See [`Context`] for more details on how library authors should use this trait.
///
/// This trait can be derived using `#[derive(FromRef)]`.
///
/// [`Context`]: https://docs.rs/blueprint_sdk/latest/blueprint_sdk/extract/struct.Context.html