mark xblock as complete when grade is provided, not when grade is read
mark xblock as complete when grade is provided, not when grade is read

open-craft/xblock-group-project-v2,open-craft/xblock-group-project-v2,edx-solutions/xblock-group-project,edx-solutions/xblock-group-project,open-craft/xblock-group-project-v2,edx-solutions/xblock-group-project