add user api wrapper

pairent_frontend_react/src/API/User.js

@@ -0,0 +1,17 @@
+import axios from 'axios';
+import constants from '../constants';
+
+const { API_ROOT } = constants;
+
+class User {
+    constructor(data) {
+        this = { ...data, ...this };
+    }
+
+    static async getById(id) {
+        const data = await axios.post(API_ROOT + '/users/get', { id });
+        if (data.data['error'])
+            throw new Error(data.data['error']);
+        return new User(data.data);
+    }
+}