group filter on studentlist now only shows assigned groups for tutors.

frontend/src/components/student_list/StudentList.vue

@@ -228,15 +228,15 @@ export default {
       return []
     },
     groups () {
-      return Assignments.state.groups.slice().sort((a, b) => {
-        const matches_a = a.name.match(/(\d+)/)
-        const number_a = Number(matches_a === null ? 0 : matches_a[1])
-
-        const matches_b = b.name.match(/(\d+)/)
-        const number_b = Number(matches_b === null ? 0 : matches_b[1])
-
-        return (number_a<number_b?-1:(number_a>number_b?1:0))
-      })
+      if (Authentication.isTutor) {
+        return Authentication.state.user.exerciseGroups
+      }
+      else if (Authentication.isReviewer) {
+        return Assignments.state.groups
+      }
+      else {
+        return []
+      }
     },
   },
   created () {