When a transaction fails in certification phase, it has connsumed one GTID, but as
transaction must rollback, it will not go for commit ordering, and because of this
also the wsrep XID checkpointing can happen out of order.
This PR will make the thread, which has failed for certiication failure to wait for its
commit order turn for checkpointing wsrep IXD in innodb rollback segment.

There is a specific test for wsrep XID checkpointing ordering in mtr test:
mysql-wsrep-bugs-607, which is added in this PR.

Test galera_slave_replay depends also on this fix, as the second test phase
may also assert for bad wsrep XID checkpointing order.
galera_slave_replay.test had also other problems, which caused the test to
fail immediately, thse are now fixes in this PR as well.