fix: Allow users with report_manage permission to access CSAT reports (#11625)

- Extended CsatSurveyResponsePolicy to support report_manage permission
- Added enterprise extension module following existing pattern
- Users with report_manage custom role can now access CSAT index,
metrics, and download
- Added comprehensive tests for both base and enterprise policy behavior

app/policies/csat_survey_response_policy.rb

@@ -11,3 +11,5 @@ class CsatSurveyResponsePolicy < ApplicationPolicy
     @account_user.administrator?
   end
 end
+
+CsatSurveyResponsePolicy.prepend_mod_with('CsatSurveyResponsePolicy')