Update view-order-details.php

Reference to [#2005](https://github.com/easydigitaldownloads/Easy-Digital-Downloads/pull/2005/files)
added 
```php
do_action ('edd_view_order_details_files_after', $payment_id);
```
back where it was and created a new action
```php
do_action ('edd_view_order_details_files_inside', $payment_id);
```
for the inside of Purchased Downloads