Add an Origin/Referer header Jetty filter

Create a new Jetty filter that allows a NiFi administrator to enable Origin/Referer HTTP header filtering.

• If the source origin header does not match the target origin, check the referer header.
• If the referer header does not match the target origin, deny the request.
• The filter should enabled or disabled using a property in the NiFiProperties configuration file.
• The filter will only be required when NiFi is configured to use HTTPS.