Fixed: Skyboxes that have been moved now reset properly on map reset

This MR changes the behavior of the SkyPicker object to remain spawned regardless of whether it's on a server or offline and to always reset it on a map reset.

This fixes 0004174, as originally when the Skybox was moved, it was flagged to be deleted and replaced with a new one on map reset, but Sky Pickers no longer existed to set the new sky, resulting in the Skybox vanishing in subsequent rounds on the same level.