Lots bounce emails related fixes

- Show bounce score on user admin page
- Added reset bounce score button on user admin page
- Only whitelisted email types are sent to emails with high bounce score
- FIX: properly detect bounces even when there is no TO: header in the email
- Don't desactivate a user when reaching the bounce threshold

app/controllers/admin/users_controller.rb

@@ -23,7 +23,8 @@ class Admin::UsersController < Admin::AdminController
                                     :primary_group,
                                     :generate_api_key,
                                     :revoke_api_key,
-                                    :anonymize]
+                                    :anonymize,
+                                    :reset_bounce_score]
 
   def index
     users = ::AdminUserIndexQuery.new(params).find_users
@@ -355,6 +356,12 @@ class Admin::UsersController < Admin::AdminController
     end
   end
 
+  def reset_bounce_score
+    guardian.ensure_can_reset_bounce_score!(@user)
+    @user.user_stat.update_columns(bounce_score: 0, reset_bounce_score_after: nil)
+    render json: success_json
+  end
+
   private
 
     def fetch_user