Refactored most templates in sections corresponding to groups

core/fixtures/initial_data.json

core/fixtures/load_inital.json

core/fixtures/testdata-core.json

core/fixtures/testdata-groups.json

core/fixtures/testdata-user.json

core/templates/base.html

core/templates/core/component/feedback_badge.html

core/templates/core/component/feedback_card.html

core/templates/core/component/message_box.html

core/templates/core/feedback_form.html

core/templates/core/index.html

core/templates/core/r/feedback_list.html

core/templates/core/r/progress_card.html

core/templates/core/r/reviewer_base.html

core/templates/core/r/reviewer_startpage.html

core/templates/core/r/student_submission_list.html

core/templates/core/r/tutor_list_card.html

core/templates/core/reviewer_startpage.html

core/templates/core/s/student_startpage.html

core/templates/core/student_submission_list.html