[Store select / multiselect] Support getOptions() via option provider

[BlackbitDevs]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no

Currently it is not possible to fetch the available options for store select / multiselect field types as you would normally do for Pimcore default select / multiselect fields via

$object->getClass()->getFieldDefinition('store')->getOptions(); // returns always null
DataObject\Service::getOptionsForSelectField($object, "store"); // also returns always null

This is currently always null as the logic for fetching the available options is only implemented in JS, see

CoreShop/src/CoreShop/Bundle/StoreBundle/Resources/public/pimcore/js/coreExtension/tags/coreShopStoreMultiselect.js

Line 17 in 99bbb0c

storeName: 'coreshop_stores'

and

CoreShop/src/CoreShop/Bundle/ResourceBundle/Resources/public/pimcore/js/coreExtension/tags/multiselect.js

Line 23 in 99bbb0c

store = pimcore.globalmanager.get(this.storeName);

It works currently only because Pimcore does not check if the set option is actually available in Select::checkValidity() / Multiselect::checkValidity() in https://github.com/pimcore/pimcore/blob/d0b5dc0d78392ee2d4012d228214901fd1080076/models/DataObject/ClassDefinition/Data/Select.php#L373
But this may change and nevertheless it is a good idea to support the same logic like Pimcore's default field types do.

[dpfaffenbauer]

PSALM is failing for other reasons. Interesting that it does that all the time. it passes and a bit later finds new issues :/.

But has nothing todo with your pr. so thanks for your contribution.