[Template] Fix first and third person delta time usage

[Eideren]

PR Details

Some points in the template use this.GetSimulation().FixedTimeStep as the delta time, that represents the delta between fixed update of the physics simulation, not the delta between each update of the game loop. It also tends to apply that delta to mouse input, which leads to sluggish controls.

Also very small change to camera interpolation for TPP, the camera now comes slightly faster to rest, easier to gauge distances to jump when the camera is not rotating.

Related Issue

None.

Motivation and Context

Fix bug.

Types of changes

• [ ] Docs change / refactoring / dependency upgrade
• [x] 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.
• [x] All new and existing tests passed.