When fulltext/advanced search is enabled, search builder can return nulls in resource list

[TipzCM]

If ElasticSearch is supported, any attempt to load resources will result in null values being returned.

This can cause some callers, like MdmLoader, to fail, as they do not expect to get back null values.

Reproduction:
1 enable both "AdvancedHibernateSearchIndexing" and "StoreResourcesInHibernateSearchIndex"
2 Create a single subscription
3 Load existing resources from db into cache (for subscriptions)

Result: error

Expected: no errors