Investigate a need for Scoped lifetimes

[bijington]

Scoped lifetimes around the lifetime of a GameScene feels like it could have some merit. It shouldn't be the only way to use the system though and will require some investigation.

Perhaps some extension to the UseOrbitEngine to accept options like:

.UseOrbitEngine(options =>
{
    options.ScopedLifetimesByScene = true;
});