Rename OccurrenceReportsComparerEntity to Finding*

Rename Vulnerabilities::OccurrenceReportsComparerEntity to
Vulnerabilities::FindingReportsComparerEntity
Rename files and test

ee/app/serializers/vulnerabilities/occurrence_reports_comparer_entity.rb → ee/app/serializers/vulnerabilities/finding_reports_comparer_entity.rb

 # frozen_string_literal: true
 
-class Vulnerabilities::OccurrenceReportsComparerEntity < Grape::Entity
+class Vulnerabilities::FindingReportsComparerEntity < Grape::Entity
   include RequestAwareEntity
 
   expose :base_report_created_at

ee/app/serializers/vulnerabilities/occurrence_diff_serializer.rb

@@ -3,5 +3,5 @@
 class Vulnerabilities::OccurrenceDiffSerializer < BaseSerializer
   include WithPagination
 
-  entity Vulnerabilities::OccurrenceReportsComparerEntity
+  entity Vulnerabilities::FindingReportsComparerEntity
 end

ee/spec/serializers/vulnerabilities/occurrence_reports_comparer_entity_spec.rb → ee/spec/serializers/vulnerabilities/finding_reports_comparer_entity_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-describe Vulnerabilities::OccurrenceReportsComparerEntity do
+describe Vulnerabilities::FindingReportsComparerEntity do
   describe 'container scanning report comparison' do
     let_it_be(:user) { create(:user) }