Fix `DetailableBehavior` bug on `Model::saveAll`. Closes #2.

Dirty workaround but required. 

* added the `bypass` option to avoid the `CommonDetailModel::save` call being run by default (effectively disabling it on `Model::saveAll`),
* added the `DetailableBehavior::beforeValidate` that unsets the detailed data to avoid breaking it by the `Model::validateMany`.