url: introduce `git_net_url_matches_pattern_list`
Provide a utility method on a url to determine if it matches any pattern
in a comma-separated list, similar to what one would find in `NO_PROXY`
environment variables.
url: introduce `git_net_url_matches_pattern`
Provide a method to determine if a given URL matches a host:port pattern
like the ones found in `NO_PROXY` environment variables.