BHoM UI Settings in Grasshopper UI

[michaelhoehn]

Description:

In view of this PR BHoM/BHoM_UI#482 around allowing the user to select which disciplines/namespaces they want to have search visibility over. I'd like to see some GH-specific QoL adjustments added to this branch https://github.com/BHoM/Grasshopper_UI/tree/BHoM_UI-%23215-Settings as it's already a great starting point.

1. Updated settings icon (red themed gear)
2. Boolean UI toggle component instead of double spike, self-deleting node