can't change the parameters of the street component for a scene loaded from JSON

[Algorush]

After loading the scene from JSON, the #default-street element does not have a street component, meaning we cannot change its properties such as showAnimation, sowGround, ...

[kfarr]

As a user, I wish to change street and streetmix-loader parameters upon reloading a saved scene. Including the option to regenerate the street from streetmix or change the URL to another street

[Algorush]

I propose the following solution to make it possible to change the parameters of the street and streetmix-loader components after loading a scene from a JSON file.

1. avoid renaming street to not-street and streetmix-loader to not-streetmix-loader.
2. Don't call init/update methods of the street and streetmix-loader when loading scene with these components from JSON. To do this I will add a global variable: STREET.sourceType = jsonFile/streetmix/streetplan.

And then make ability to change street component parameters without scene reloading: https://github.com/3DStreet/3dstreet/issues/511