Use node-fetch instead of request (#6228)

* requestをnode-fetchになど

* format

* fix error

* t

* Fix test

src/remote/activitypub/resolver.ts

@@ -1,10 +1,8 @@
-import * as request from 'request-promise-native';
+import { getJson } from '../../misc/fetch';
 import { IObject, isCollectionOrOrderedCollection, ICollection, IOrderedCollection } from './type';
-import config from '../../config';
 
 export default class Resolver {
 	private history: Set<string>;
-	private timeout = 10 * 1000;
 
 	constructor() {
 		this.history = new Set();
@@ -41,24 +39,7 @@ export default class Resolver {
 
 		this.history.add(value);
 
-		const object = await request({
-			url: value,
-			proxy: config.proxy,
-			timeout: this.timeout,
-			forever: true,
-			headers: {
-				'User-Agent': config.userAgent,
-				Accept: 'application/activity+json, application/ld+json'
-			},
-			json: true
-		}).catch(e => {
-			const message = `${e.name}: ${e.message ? e.message.substr(0, 200) : undefined}, url=${value}`;
-			throw {
-				name: e.name,
-				statusCode: e.statusCode,
-				message,
-			};
-		});
+		const object = await getJson(value, 'application/activity+json, application/ld+json');
 
 		if (object == null || (
 			Array.isArray(object['@context']) ?