ITVR - automate sending/receiving of CRA files

[tim738745]

Description:
The CRA's file server is transitioning over to SFTP from FTP; this requires us to supply them with a public key for authentication and a list of IP addresses for whitelisting. Our current method of sending/receiving files from them would no longer be feasible under this new model. Therefore, we should automate the file transfer process.

Development Checklist:
(1) Create a SSH key pair (https://www.ssh.com/academy/ssh/keygen)
(2) Create a periodic job that generates and uploads a file to the CRA using SFTP (can use this library: https://docs.paramiko.org/en/latest/index.html).
(3) Create a periodic job that retrieves and processes a file returned from the CRA using SFTP.
(4) Ensure that a file is not sent to the CRA before the previous file has been successfully retrieved and processed (can use the file's sequence number to track this).

Notes:
The jobs mentioned in (2) and (3) of the development checklist should use the generated SSH private key when connecting to the file server.

[danclancy85]

ITVR System being shut down. Blocks further progress on this card. Move to blocked until we get further direction on restarting ITVR.

[danclancy85]

Tested and approved. The process has been tested with the CRA's server and functions correctly.