fix: Improve API doc for OnGainedOwnership and OnLostOwnership

[jabbacakes]

Updating the API doc for NetworkBehaviour.OnGainedOwnership and NetworkBehaviour.OnLostOwnership, per issue 1255 in the docs repo.

@NoelStephensUnity Please make sure you have a close look at the edits for client-server vs. distributed authority contexts. Pretty sure I got it right based on our chat yesterday, but need your eyes to be sure 👀

Equivalent PR for 1.x version is here: #2996

Changelog

• Fixed: Added more detail to the API doc for NetworkBehaviour.OnGainedOwnership and NetworkBehaviour.OnLostOwnership.

Testing and Documentation

• Includes edits to existing public API documentation.

[unity-cla-assistant]

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