Implement teachers-field

aleksis/apps/chronos/frontend/components/Substitutions.vue

@@ -39,6 +39,18 @@ import CRUDList from "aleksis.core/components/generic/CRUDList.vue";
         TODO 18n all day
       </span>
     </template>
+    <template #teachers="{ item: { oldTeachers, newTeachers } }">
+      <span v-if="newTeachers.length > 0">
+        <strike v-for="t in oldTeachers"> {{ t.shortName || t.fullName }} </strike>
+        <span> &nbsp;→&nbsp </span>
+        <b v-for="t in newTeachers"> {{ t.shortName || t.fullName }} </b>
+      </span>
+      <span
+        v-else
+        v-for="t in oldTeachers"
+      > {{ t.shortName || t.fullName }} </span>
+    </template>
+    </template>
   </c-r-u-d-list>
 </template>