SFTP classes
We need SFTP capabilities https://api.libssh.org/stable/libssh_tutor_sftp.html
This is what I'm thinking
SFTPSession
mkdir : bool
rmdir : bool
openFile(string, access_type) : SFTPFile
openDir(string) : SFTPDir
error() : string
canonicalize (string) : string
SFTPFile
write(string) : size_t
read(size_t) : string
close() : bool
seek() : size_t
tell() : size_t
SFTPDir
hasNext() : bool <-- sftp_dir_eof(dir)
next() : struct imitating sftp_attributes_struct with c++ types.