Admin reports with accounts (#2092)

* Add a ReportFilter class

* Add reports and targeted_reports relationships to Account

* Use ReportFilter from admin/reports controller

* Link to admin/reports filtered views from admin account show view

* Add indexes to reports.account_id and reports.target_account_id

spec/models/report_filter_spec.rb

@@ -0,0 +1,31 @@
+require 'rails_helper'
+
+describe ReportFilter do
+  describe 'with empty params' do
+    it 'defaults to unresolved reports list' do
+      filter = ReportFilter.new({})
+
+      expect(filter.results).to eq Report.unresolved
+    end
+  end
+
+  describe 'with invalid params' do
+    it 'raises with key error' do
+      filter = ReportFilter.new(wrong: true)
+
+      expect { filter.results }.to raise_error(/wrong/)
+    end
+  end
+
+  describe 'with valid params' do
+    it 'combines filters on Report' do
+      filter = ReportFilter.new(account_id: '123', resolved: true)
+
+      allow(Report).to receive(:where).and_return(Report.none)
+      allow(Report).to receive(:resolved).and_return(Report.none)
+      filter.results
+      expect(Report).to have_received(:where).with(account_id: '123')
+      expect(Report).to have_received(:resolved)
+    end
+  end
+end