Validation Framework improvements

[e-t-k]

Updates to the validation framework:

• [x] Kick off a validation automatically when the submission is fully uploaded

  • turns out the after_request decorator or teardown_request are inappropriate as they still call before response. Will need a task queue. stackoverflow with helpful explanation

• [x] Additional test cases!

• [x] Turn validations into functions, not classes

  • [x] use a standardized signature & name prefix, eg validate_

• [x] set up the validator module to introspect for all found validation functions and run in a queue

  • this makes it very easy to add additional validations upon request

[e-t-k]

Per Rob,

• [x] pull out the spooler endpoint into a separate file that has access to the DB but doesn't use Flask.

[e-t-k]

Final improvements added in 8244222a67fcb2ef225397dc299785ac2ee15564 - tests & introspection for validate fns.