Rename SignatureSheet column

This new functionality will allow to retrieve in the signature sheet
the document number, the date of birth and the postal code.

So we renamed :document_numbers to :required_fields_to_veriry to
clarify and adjust the name to its use.

app/controllers/admin/signature_sheets_controller.rb

@@ -27,7 +27,7 @@ class Admin::SignatureSheetsController < Admin::BaseController
   private
 
     def signature_sheet_params
-      params.require(:signature_sheet).permit(:signable_type, :signable_id, :document_numbers)
+      params.require(:signature_sheet).permit(:signable_type, :signable_id, :required_fields_to_verify)
     end
 
 end