MODE-1834 Corrected logic that creates workspaces when used with PESSIMISTIC locking

When Infinispan's PESSIMISTIC locking mode is enabled, ModeShape failed
to create workspaces. This is because PESSIMISTIC mode apparently
requires explicit transactions.

Two test cases were added to verify the functionality with different
Infinispan configurations (PESSIMISTIC and OPTIMISTIC). There were
already test cases for other configuration.