Resolve "Add export functionality to course book"

Closes #258 (closed)

aleksis/apps/alsijil/frontend/components/coursebook/CoursebookControls.vue

@@ -71,6 +71,7 @@ import CoursebookPrintDialog from "./CoursebookPrintDialog.vue";
       </v-btn>
       <coursebook-print-dialog
         v-if="pageType === 'documentations'"
+        :loading="selectLoading"
       />
     </div>
   </div>