As discussed in the UI Module Meeting we don't have an acceptable use
case for dialogs that use the Blender logo. Removing this image from
the project since this is now exposed through dialog customization.
Pull Request: https://projects.blender.org/blender/blender/pulls/117676
Change to monochrome version of the large alert icons and use 'Question' for the the Quit Confirm dialog box.
Differential Revision: https://developer.blender.org/D9062
Reviewed by Pablo Vazquez
Harley Acheson
