Update templates and sample code to better support pausing

[ds5678]

PR Details

A couple places incorrectly used Game.DrawTime in an Update method. I replaced them with with Game.UpdateTime.

#2999 says that the proper way to do game pausing for animations, particles, and physics is to set Game.UpdateTime.Factor to zero. However, most of the sample code used Game.UpdateTime.Elapsed instead of Game.UpdateTime.WarpElapsed. Game.UpdateTime.WarpElapsed is equal to Game.UpdateTime.Factor * Game.UpdateTime.Elapsed. Both are automatically calculated every frame, so there is no performance difference for using one over the other.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have built and run the editor to try this change out.