GroupBy JSON Entity

[smitpatel]

Variation for #17653

When grouping by an entity, we add all the columns of the entity in the grouping key.
For entity which are mapped as JSON,

• Should we add all the properties? If yes, how would we add the ordinal property which is non-persisted.
• Given the JSON entity is going to be single SQL function call, we can just add the function call.

First option aligns with regular entity but would cause a lot of JSON scalar function calls. Second option will only have one call but the grouping key will contain owned entities in aggregate too. Further, grouping by a large JSON blob may not be something which user should do.