fix: do't transform big file to base64

packages/client/src/services/file.ts

@@ -1,7 +1,12 @@
-import { string } from 'lib0';
 import { HttpClient } from './HttpClient';
 
+const ONE_MB = 1 * 1024 * 1024;
+
 export const readFileAsDataURL = (file): Promise<string | ArrayBuffer> => {
+  if (file.size > ONE_MB) {
+    return Promise.reject(new Error('文件过大，请实现文件上传到存储服务！'));
+  }
+
   return new Promise((resolve) => {
     const reader = new FileReader();
     reader.addEventListener('load', (e) => resolve(e.target.result), { once: true });