Add let-chain support for convert_to_guarded_return

[A4-Tacks]

• And add early expression None in function Option return

Example

fn main() {
    if$0 let Ok(x) = Err(92)
        && x < 30
        && let Some(y) = Some(8)
    {
        foo(x, y);
    }
}

->

fn main() {
    let Ok(x) = Err(92) else { return };
    if x >= 30 {
        return;
    }
    let Some(y) = Some(8) else { return };
    foo(x, y);
}