Fixing several non-critical bugs and enhancements that should make workflow a little cleaner and placeable_instance rendering colors correctly.

Enhancements

• Added an option validate_on_ready to BuildingStateLevelSetter to optionally validate the building state on ready. By default this is turned off. If you have multiple BuildingStateLevelSetters or other objects interacting with the BuildingState, you may want to enable it on the last loaded Level Setter to prevent unnecessary and inaccurate warning messages. BuildingSystem also validates the state on call, so you may leave this off entirely.

Bug Fixes

• Fixed a bug where GBValidator was not running on initiation for objects that passed in p_start _init parameter as true.
• Fixed a bug where null instances of Placeable PackedScenes were not sending warning message for improper setup.
• Fixed a bug where preview instances were not rendering preview colors correctly. Now modulate should set on the root and automatically effect child canvas items.