Add guard support for replace_if_let_with_match

[A4-Tacks]

Support let-chain to guard and fix some indent

Example

fn main() {
    if $0let true = true
        && true
        && false
    {
        code()
    }
}

->

fn main() {
    match true {
        true if true
            && false => code(),
        _ => (),
    }
}