fix: host not generating its own local client disconnect notification

[NoelStephensUnity]

This fix assures a host will invoke OnClientDisconnectCallback for its local client when it is internally shutting down.

fix: #2789

Changelog

• Fixed: Issue where the host was not invoking OnClientDisconnectCallback for its own local client when internally shutting down.

Testing and Documentation

• Includes integration test update.
• No documentation changes or additions were necessary.