How to handle spawn-despawn for Prespawned entities before we receive the server entity?

[cBournhonesque]

Scenario:

• client C spawns entity E that is Prespawned
• C despawns E (with prediction_despawn())
• Server message containing E' arrives.

How do we handle the despawn?

Option 1: we really despawn E, and we clear out the prespawn hash map

• when client receives E', it tries to match it with E using the prespawned hash. It sees that E is missing so it just spawns a new predicted entity. The predicted entity has no history for that tick so a rollback happens for that entity

Option 2: we do a fake despawn for E, and update its history immediately.

• client receives E', we match it with E using the prespawned hash. There is no rollback because we kept the PredictionHistory on the Predicted entity even though we removed all other components.

Problem:

• if the entity is spawned/despawned within a replication interval on the server (because it is very short-lived), then the server won't ever send a message for that entity. This is fine because the entity will be cleaned up by pre_spawned_player_object_cleanup anyway
• the non-networked components on the PreSpawned entity are not removed (same problem as Move PredictionHistory to the Confirmed entity? #793)

It seems like we should just do the same thing as we do for Predicted entities.