A malicious or compromised FTP server could include control characters
(e.g. bare \r, or bytes 0x01-0x1f/0x7f) inside the quoted directory path
of its 257 PWD response. That string is stored verbatim as
ftpc->entrypath and later sent unescaped in a CWD command on connection
reuse via Curl_pp_sendf(), which performs no sanitization before
appending \r\n.
Reject the entire path if any control character is encountered during
extraction so that tainted data never reaches a subsequent FTP command.
Add test case 3217 and 3218 to verify. Adjusted test 1152 accordingly.
Closes#20949
