Add support for XNAT CSRF tokens
If CSRF tokens are enabled in Administer -> Site Administration -> Security on XNAT, the XNAT endpoints used in this application require a CSRF token.
CSRF token verification is a useful security feature for the admin interface and we should support it. However this application does not have access to the CSRF tokens generated by XNAT's velocity template engine, since it not rendered by it.
Notes:
- https://groups.google.com/g/xnat_discussion/c/EWLo8gunL44/m/cWhpNNcvBQAJ according to this thread, xnat uses the user-agent string to determine whether or not to apply CSRF verification. Maybe we can change the user agent of our client.