Take a comopsite snapshot whenever you want

The scene-to-composite functionality allows me to take a snapshot of the scene with it's state as soon as the scene first loads. This is great for migrating many scenes, but in some cases this will only represent a fraction of the content in my scene, maybe the scene is waiting on a server request or for the player to move from the starting position to load more of the content.

For example in the original Genesis Plaza, the NPCs and other content downstairs in the bar wont' load till I go down.

If we want to migrate this content, we should take the snapshot at an arbitrary time after the initial load.

Proposal: offer a button on the debug pannel that lets me take a snapshot whenever I think is the right time. This will carry out the same as scene-to-composite, commenting out all code and capturing the current state of all entities and components being rendered.

When doing this we should be prompted with a warning, as this action has serious impact on the scene.