Prepare bank transfers

Creates and leaves a batch of transfers pending for approval,
these bank transfers can be between accounts of the same or different banks,
which allows multiple transfers to be processed together in a single request.
This endpoint is designed to allow transfers to be reviewed and approved by an administrator
user from the Mono app before being sent to the banks.

When the server receives the request, it will process the batch of transfers and create transfer records in our database
for each of them, the transfers will not be executed immediately, instead, the batch will be queued for
review and approval by an administrator user from Mono app.

Considerations:

1. API key roles allowed to consume this endpoint are "Administrator" and "Preparer".
2. The minimum number of transfers allowed per batch is 1.
3. The maximum number of transfers allowed per batch are 1.000.