MDL-44637 events: Created a tool for listing all events.
MDL-44637 events: Update to core/event/base to return core event information.
MDL-44637 events: Update to core/event/manager to return observer information.
MDL-44637 events: Update to string that was throwing off event list column ordering.
MDL-44637 events: Behat tests for the event listing tool.