ability to change street component parameters without scene reloading

[Algorush]

As it is now: if user change a street component parameter, such as showGrounding, showVehicles, the scene is reloaded with new parameters. A new parsing of StreetmixJSON data occurs and all objects take new places. What would be better: when changing the street parameters, the scene does not reload, all objects remain in place. Why is this important: if the user adds new objects to the scene or changes the location of existing objects, then when changing the street parameters, all new objects will be lost, as well as the location of existing objects.

[Algorush]

https://github.com/3DStreet/3dstreet/pull/512