Batch assign/unassign card definitions

<Warning>

<Badge color="yellow">BETA endpoint</Badge>

This is a work-in-progress documentation of a BETA endpoint. The parameters, fields, request and response bodies, and other data may subject to change. If you want to share feedback or improvements, contact Voucherify support or your Technical Account Manager.

</Warning>

Assigns and/or unassigns card definitions to/from a program in a single batch. Unassign operations are processed before assign operations. The program must be in DRAFT status - otherwise the request is rejected with 423 Locked (key non_draft_program). In strict mode (default) missing card definitions, inactive card definitions or missing assignments cause the whole batch to fail.