Reflect canEdit in documentation modal's buttons

aleksis/apps/alsijil/frontend/components/coursebook/documentation/Documentation.vue

@@ -26,8 +26,9 @@
     <v-divider />
     <v-card-actions v-if="!compact">
       <v-spacer />
-      <cancel-button @click="$emit('close')" :disabled="loading" />
-      <save-button @click="save" :loading="loading" />
+      <cancel-button v-if="documentation.canEdit" @click="$emit('close')" :disabled="loading" />
+      <save-button v-if="documentation.canEdit" @click="save" :loading="loading" />
+      <cancel-button v-if="!documentation.canEdit" i18n-key="actions.close" @click="$emit('close')"/>
     </v-card-actions>
   </v-card>
 </template>