Make StorageNode.EntityFetchQueryCache per-Domain

[SergeiPavlov]

This cache's key & value don't depend on StorageNode.
We need not ~1700 copies of the cache

Also:

• Refactor HashCode calculation
• Make EntitySetFetchQueryCache & RefsToEntityQueryCache per-Domain as well
• Refactor GetColumnsToBeLoaded() to return array instead of List<>, because it always stored in Cache
• Make RootContainerCacheEntry record struct
• Make PersistenceState a byte enum to save each Entity size
• Make TypeReferenceAccuracy a byte enum

[botinko]

Wow much better approach!