feat: function clearSceneApp to de-cache initialized scene apps so that they can be fully reinitialized

[darrenjaneczek]

This supports a use case to completely refresh a scene app when in the event of an app plugin configuration change.
There are many ways to solve this problem, but this may be a useful option to speed up developer experience, to be used when a complete re-init of a scene app is acceptable UX.

[darrenjaneczek]

Closed. I think we're going to try to encourage better use of SceneVariables so that these brute force approaches aren't necessary.

I think it might be better to think how to invalidate this specific data / metric names., instead of the whole app