chore: test project update

[NoelStephensUnity]

More minor updates to test project:

• Properly reset GenericNetworkObjectBehaviour when despawned to assure respawning has no remaining artifacts from last spawn.
• NetworkPrefabPool now sets the pooled object's position and rotation to that of the NetworkPrefabPool when despawning the pooled object.
• Added ShutdownWhenNoClients component which could be a useful example for users wanting to handle shutting down a DGS when all clients have disconnected.

Changelog

N.A.

Testing and Documentation

• No tests have been added.
• No documentation changes or additions were necessary.

[michalChrobot]

Hey, I was wondering if this is still valid or can we close this PR? (I'm just doing a check through PRs and Issues)