Create Additive debug scene

[jChicote]

Description

Create a scene with additive scenes to test enemy systems replacements within an additive scene environment

[jChicote]

Additional Requirements:

• Reimplement ability to navigate back to deloaded scene
• Implement a 3-tiled additive scene system. Active scene has all enemies, environment and services enabled. Outer scenes only have the environment loaded, but all enemy systems and scene management services disabled.