Format Dictionary to url query

Dictionary+UrlQuery.swift

extension Dictionary {
    func urlQueryEncode() -> String {
        return self
            .map({ "\($0)=\($1)" })
            .joined(separator: "&")
            .addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
    }
  
    func queryParameters() -> String {
        let parameterArray = self.map { (key, value) -> String in
            return String(format: "%@=%@",
                          String(describing: key).addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!,
                          String(describing: value).addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!)
        }
        return parameterArray.joined(separator: "&")
    }
}