Improve new assignments Look and feel

Be aware on all styling on assignment activity. As a student navigate to an assignment that has been reopened. Check button with text "Add a new attempt based on previous submission" is now well styled (less padding). As a teacher navigate to an assignment with a little of previous activity (grading and submissions). Check that the number of participants and all its tpes are inside blue badges. Enter to the participants list. Check it only displays one of the two badges when possible (ie No submission and no grade only displays No submission) Enter into a submission. Check tab styling is using full width. Check that the previous save button is now the "Done" text on top right header bar. Check fields have been reordered following UX-13. Check listed files on submission / feedback have no borders.