A certification failure followed by a clean shutdown would cause an
inconsistency between the sequence number stored in innodb and the
sequence number stored in provider.
This happened both in the case of local certification failure, and in
the case where dummy writeset is applied.
The fix consists of:
- updating wsrep position after dummy writeset is delivered in
 `Wsrep_high_priority_service::log_dummy_write_set()`
- updating wsrep position while releasing commit order in wsrep-lib
 side

Added two tests which stress the situation where a server is shutdown
after a certification failure.