Bug 30719: DB and API

Bug 30719: DB and API

- Adds 'batch' accessor to Illrequest object
- New illbatches and illbatch_statuses tables
- New foreign key 'batch_id' in illrequests table
- Atomic update file
- Default illbatch_statuses
- Add 'add' ill_requests api method
- Add POST method in ill_requests path
- Add 'batch_id property to ill_request api definition
- Updated swagger.yml with new batches and batchstatuses endpoints

Co-authored-by: Andrew Isherwood <andrew.isherwood@ptfs-europe.com>
Signed-off-by: Edith Speller <Edith.Speller@ukhsa.gov.uk>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>