/**
 * FtpClient is a crawler client implementation for accessing resources via the FTP protocol.
 * It extends {@link AbstractCrawlerClient} and provides methods to retrieve content and metadata
 * from FTP servers. The client supports various configurations, including authentication, timeouts,
 * passive/active modes, and encoding settings. It also handles FTP file attributes such as user,
 * group, and symbolic links.
 *
 * <p>