NodeInstanceLog for node left events should be fired on beforeNodeLeft

As a result, the order seems strange, so from all events happening as a result of completing the self evaluation task for example:

• before self left
• before join triggered (***)
• before join left
• before HR triggered (***)
• after HR triggered
• after join left (***)
• before join left
• before PM triggered (***)
• after PM triggered
• after join left (***)
• after join triggered
• after self left (***)

The ones with (***) are when the event is created, resulting in strange order:
join triggered
HR triggered
join left
PM triggered
join left
self left

I guess the expected order would match with all before events:
self completed
join triggered
join left
HR triggered
join left
PM triggered

https://github.com/kiegroup/jbpm/blob/master/jbpm-audit/src/main/java/org/jbpm/process/audit/JPAWorkingMemoryDbLogger.java

• For nodes being triggered, we create the event related to that on before (line 119)
• For nodes being left, we create the event related to that only on after (line 126)