If the ESC table has N rows, the N-1 rows should be deleted with a delete that is not in a MongoDB user transaction. Normally, all of the ESC operations run in SyncTransactionWithRetries::runNoThrow` which means they run in a TXN. Due to the large number of ESC rows that must be deleted this could create a very large txn, the deletes should instead happen with a delete that does not run as part of the transaction.

1. Extend FLEQueryInterfaceImpl with a new delete method
See FLEQueryInterfaceImpl::countDocuments for example of how this can be done with DBDirectClient
2. Change ESC deletes to use this new method for all but the highest ESC record.

Note: ECC deletes remain under the txn. Also, the ESC null document update remains under the TXN.