优化mongo，封装count逻辑，处理objectId

mongo/mongo.go

@@ -238,6 +238,9 @@ func (m *MongoDB) Find(ctx context.Context, filter bson.M, result interface{}, c
 	optionsKey := fmt.Sprintf("%+v%+v", page, orderBy)
 	redisKey := fmt.Sprintf(redis.List, user.TenantId, collection, filterKey, optionsKey)
 	resultValue := reflect.ValueOf(result)
+	if resultValue.IsNil() || resultValue.IsZero() {
+		return errors.New("result不能为空")
+	}
 	resultValue = resultValue.Elem()
 	listField := resultValue.FieldByName("List")
 	if m.Cache {