Limit number of files that can be submitted, other bugfixes

[patrick-austin]

• Limit number of files that can be submitted and remove the chunking into parts for /queue/files
• Calculate a running total for the fileSize of queued Downloads and set this directly instead of using the IDS
• 400 and 404 errors for submitting bad visitIds/files or those that do not exist/do not pass authz
• Only call performCheck when there's a prepardId to use
• Properly extract the functional sessionId used to prepare queued Downloads
• Tests
• Add options to the admin script for queue related things

[kevinphippsstfc]

These 7 lines are a copy of those just above, so should go in a separate method to avoid duplication. There was some duplication previously but it is now worse with the use of the new response object and the additional values being populated.

[kevinphippsstfc]

Is there a reason why you didn't use a SELECT SUM query here? I think the ICAT API supports them.

[kevinphippsstfc]

I think the return value in the javadoc needs updating. If I understand correctly it is no longer an array of download IDs but a single download ID and an array containing any missing files.

[patrick-austin]

Also includes fix for a NullPointer when anonUserName is undefined, with a warn when starting the API if anonUserName is undefined to say that this will mean we cannot distinguish anon and authenticated users, so everyone will use authenticated priority (which is at least as high a priority as default).