Student finance mod dashboard text and drop submitted from user stages

Correct device type display text on dashboard and module
Change 'Completion at each step' to 'Users at each stage' - the visualisation does not show completion
Drop 'Submitted' user stage from visualisation - reports wrong data
Merge pull request #257 from alphagov/student-finance-mod-dashboard-text-and-drop-submitted-from-user-stages

Student finance mod dashboard text and drop submitted from user stages