Modify End Session endpoint to support list of patronId

Modify existing End Session end point to support list of patronId according to the requirements of CIRC-412:

Scenario 1 - Check in

FOLIO operator opens check in screen
Then scans 7 items borrowed by Patron A
Then scans 10 items borrowed by Patron B
Then scans 2 items borrowed by Patron C
Then ends session (notices are sent to Patrons A with the 7 items, B with the 10 items and C with the 2 items)

The existing End Session endpoint supports only one patronId for request