This change introduces two new fields supported by the write commands:
- txnNum - an always-increasing int64_t value, relative to the session under which the write was executed. This value uniquely identifies the write so that when retry is requested the server does not re-execute it if it already happened.
- stmtIds - this is an array of int32_t values of the same size as the number of entries in the inserts/updates/deletes array of the write, uniquely indicating each write from the batch. Again, this is for retriability purposes.
This task is to add support for txnId and stmtId fields to the write commands as per the design specification. It includes the work to read and write both implicit and explicit fields and correctness validation.