Fetch gradation status

ui/src/lib/grades.js

@@ -40,4 +40,16 @@ export class Grade {
       throw new Error((await res.json()).errmsg);
     }
   }
+
+  async gradationStatus() {
+    const res = await fetch(this.id_user?`api/users/${this.id_user}/works/${this.id_work}/grades/${this.id}/status`:`api/works/${this.id_work}/grades/${this.id}/status`, {
+      method: 'GET',
+      headers: {'Accept': 'application/json'},
+    });
+    if (res.status == 200) {
+      return await res.json();
+    } else {
+      throw new Error((await res.json()).errmsg);
+    }
+  }
 }