Introduce more descriptive exception message when Morphia class name changed

TypeCastException: null cannot be cast to non-null type java.lang.Class<T>
kotlin.TypeCastException: null cannot be cast to non-null type java.lang.Class<T>
	at com.neva.javarel.storage.store.impl.EntityObjectFactory.getClass(EntityObjectFactory.kt:57)
	at com.neva.javarel.storage.store.impl.EntityObjectFactory.createInstance(EntityObjectFactory.kt:15)
	at org.mongodb.morphia.mapping.Mapper.fromDBObject(Mapper.java:190)
	at org.mongodb.morphia.query.MorphiaIterator.convertItem(MorphiaIterator.java:134)
	at org.mongodb.morphia.query.MorphiaIterator.processItem(MorphiaIterator.java:146)
	at org.mongodb.morphia.query.MorphiaIterator.next(MorphiaIterator.java:117)
	at org.mongodb.morphia.query.QueryImpl.asList(QueryImpl.java:150)
	at com.neva.javarel.storage.store.api.store.DomainStore.fetchQuery(DomainStore.kt:25)
	at com.neva.javarel.storage.store.api.store.DomainStore.getAll(DomainStore.kt:12)
	at com.neva.javarel.app.sample.post.PostController.app(PostController.kt:19)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)