JAVA-5528 skipped splitting the ops and nsInfo parts of the bulkWrite command, and encoding them as separate sections of the OP_MSG wire protocol message with payload type 1; it also skipped splitting the bulkWrite command if the number of write models is too large. This ticket must implement what was skipped in JAVA-5528.

Prose spec tests are to be implemented together with this implementation because they will give us some confidence in the implementation.