ENG-5547: Dump the content of the ReplaySequencer and the TransactionTaskQueue
on the SPIs when the MPI thinks it's deadlocked.

Helps debug MPI deadlocks during command log replay.
ENG-5547: Catch any throwables in case the dump is not successful.
Merge pull request #989 from VoltDB/ENG-5547

ENG-5547: Dump the content of the ReplaySequencer and the TransactionTaskQueue when the MPI sends the dump message