ISPN-4137 Transaction executed multiple times due to forwarded CommitCommand

https://issues.jboss.org/browse/ISPN-4137

I don't have a test that triggers a topology update and re-runs the commit command (yet). But I've removed the skipTransactionCompletedCheck flag, so a commit for a command that has been already committed should now be ignored.

* Remove the "skipTransactionCompletedCheck" transaction flag.
* Only mark the transaction as completed after running the prepare from
  state transfer (if needed).
* Do not try to roll back if commit fails and recovery is enabled.