NIFI-4752: Addressed issue with some event types having potentially t…

[markap14]

…he wrong FlowFile UUID listed (could have child UUID when it's supposed to have parent flowfile UUID). In testing fix, also found an issue with Search threads not being daemon and Re-Index threads not propertly being shutdown so addressed those as well.

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[ijokarumawak]

Reviewing...

[ijokarumawak]

@markap14 Thanks for the fix! I've confirmed that WriteAheadProvenanceRepository emits provenance events FlowFile UUID as PersistentProvenanceRepository does. LGTM, +1 merging.