Vuln Detail missing painReductionEvent object

[adamstc1]

Issue: The vulnerabilityDetail schema does not include an array of painReductionEvent objects.

• The painReductionEvent object was added to the common schema but is not referenced in the vulnerabilityDetail schema.
• Per VER-RPT-VDT, providers are required to provide a historical PAIN ratings and reduction events, so there should be an array of painReductionEvents in the vulnerabilityDetail schema.
• Additionally, the description of painReductionEvent references rule "VER-RPT-PAE" which is not a FRR, probably just a typo.

Fix:

• Add painReductionEvent array to vulnerabilityDetail schema
• Fix the typo in the description of painReductionEvent