upadte csv export services to retrieve creation method values direct from the log, remove methods previously used from the log model

app/models/log.rb

@@ -178,14 +178,6 @@ class Log < ApplicationRecord
     end
   end
 
-  def creation_method_code
-    bulk_uploaded? ? 2 : 1
-  end
-
-  def creation_method_label
-    bulk_uploaded? ? "bulk upload" : "single log"
-  end
-
   def bulk_uploaded?
     bulk_upload_id.present?
   end

app/services/csv/lettings_log_csv_service.rb

@@ -108,8 +108,8 @@ module Csv
         codes: %i[scheme id_to_display],
       },
       creation_method: {
-        labels: %i[creation_method_label],
-        codes: %i[creation_method_code],
+        labels: %i[creation_method],
+        codes: %i[creation_method_before_type_cast],
       },
       is_dpo: {
         labels: %i[created_by is_dpo?],

app/services/csv/sales_log_csv_service.rb

@@ -43,8 +43,8 @@ module Csv
         codes: %i[owning_organisation name],
       },
       creation_method: {
-        labels: %i[creation_method_label],
-        codes: %i[creation_method_code],
+        labels: %i[creation_method],
+        codes: %i[creation_method_before_type_cast],
       },
     }.freeze