Update validation.php

Since this file is only used in PS v1.4, and because that the Shop class does not exist in all PS v1.4 versions,
1) we remove any usage of the Shop class. Installing backwards compat does not work on all PS v1.4 versions, so better to not even bother trying to use it.

2) We also alter the invocation of validateOrder to remove passing the Shop object. This is because in PS v1.4, validateOrder does not define this parameter and calling the function fails

3) We hardcode the id_shop to 1 when used in the "addTransaction" call.

4) The function changeIdOrderState is different in v1.4, so we need to add version compare logic for this