ISPN-3146 PrepareCommand triggers RollbackCommand in TxInterceptor if the commit arrives at the same time

Total Order only! When the CommitCommand arrives, it marks the transaction as completed.
In TxInterceptor, if the transaction is completed, a RollbackCommand is triggered.
Total Order already handles this case and the RollbackCommand will create inconsistencies.
ISPN-3097 Improve total order test suite

* the tests extend a common base test implementation.
* added more tests varying the configuration.
* before check consistency, it waits until the transaction is committed in all the nodes involved.