Add "Hide Menu on Launch" Setting

[NGenesis]

Adds a "Hide Menu on Launch" setting to support automatically hiding the ClientSim menu when initially entering play mode for rapid development iteration.

[momo-the-monster]

Looks good, and works for me. Running through internal QA process now.

[momo-the-monster]

QA found an issue - when this code is implemented, the ClientSim menu no longer appears when you press escape. This menu has helpful functions and, as a creator, I wouldn't expect the 'hide menu on launch' toggle to disable it completely.

I've got another approach working internally - closing the ClientSim menu when you move your player, similar to how the QuickMenu closes in the VRChat Client when you move. I'm putting that through QA now and un-approving this change. Let me know what you think!

[momo-the-monster]

The update inspired by this PR has just passed QA, and will go into the next SDK release:

• Adds a new ClientSim setting - "Hide Menu on Launch", which automatically closes the ClientSim pause menu when entering Play Mode, after you've accepted the warning about differences between ClientSim and the VRChat Client.
• Automatically closes the ClientSim pause menu when you move your player, similar to how the Quick Menu works in the Client.

I will close out this PR unmerged, thanks for your contribution!