This PR implements the low-level logic to use the FTPS protocol (including as a direct protocol).
Note that curl and hence FTPDownloader can already handle the protocol (see the tests implemented in c54fc89 and 288177a). However, the download service didn't allow it (we think that there was a confusion between SFTP and FTPS - see 8e9b7ff).
This PR implements the low-level logic to use the FTPS protocol (including as a direct protocol).
Note that
curland henceFTPDownloadercan already handle the protocol (see the tests implemented in c54fc89 and 288177a). However, the download service didn't allow it (we think that there was a confusion between SFTP and FTPS - see 8e9b7ff).