refactor: refactoring imports

将来ESMに移行しやすいように
Related: #7658

なんかmochaが起動しなくなってるけど理由不明
すぐ直したい

src/server/file/index.ts

@@ -3,10 +3,16 @@
  */
 
 import * as fs from 'fs';
+import { fileURLToPath } from 'url';
+import { dirname } from 'path';
 import * as Koa from 'koa';
 import * as cors from '@koa/cors';
 import * as Router from '@koa/router';
-import sendDriveFile from './send-drive-file';
+import sendDriveFile from './send-drive-file.js';
+
+//const _filename = fileURLToPath(import.meta.url);
+const _filename = __filename;
+const _dirname = dirname(_filename);
 
 // Init app
 const app = new Koa();
@@ -16,7 +22,7 @@ app.use(cors());
 const router = new Router();
 
 router.get('/app-default.jpg', ctx => {
-	const file = fs.createReadStream(`${__dirname}/assets/dummy.png`);
+	const file = fs.createReadStream(`${_dirname}/assets/dummy.png`);
 	ctx.body = file;
 	ctx.set('Content-Type', 'image/jpeg');
 	ctx.set('Cache-Control', 'max-age=31536000, immutable');