Refactor streets_configuration singleton to be composed of a separate instance class.

[paulbourelly999]

Summary

Currently the streets_configuration_singleton is a streets_singleton<streets_configuration_singleton>. This makes the code difficult to read and also causes a circle call to deconstructors if the streets_singleton deconstructor calls delete on the managed instance. This enhancement is to create a separate class for holding the streets_configuration logic and data and using that as the template type.

Reasoning for new functionality

This makes the code difficult to read and also causes a circle call to deconstructors if the streets_singleton deconstructor calls delete on the managed instance. This enhancement is to create a separate class for holding the streets_configuration logic and data and using that as the template type.