Function find_matching_rule 

pub fn find_matching_rule<'a>(
    rules: &'a [ProxyRule],
    method: &Method,
    uri: &Uri,
    headers: &HeaderMap,
    body: Option<&[u8]>,
    path_matches: impl Fn(&str, &str) -> bool,
) -> Option<&'a ProxyRule>

Find matching proxy rule with condition evaluation