Update typescript in typetest and update socket.io imports to fix compilation issue

Author: hlxid

types/lib/nodecg-instance.d.ts

@@ -1,10 +1,10 @@
 /// <reference lib="dom" />
 /// <reference types="node" />
-/// <reference types="socket.io" />
-/// <reference types="socket.io-client" />
 /// <reference types="soundjs" />
 
 import {RequestHandler, Router, RouterOptions} from 'express';
+import type * as SocketIOClient from 'socket.io-client';
+import type * as SocketIO from 'socket.io';
 
 import {Logger} from './logger';
 import {ReplicantOptions, Replicant} from './replicant';

types/lib/nodecg-static.d.ts

@@ -1,3 +1,5 @@
+import type * as SocketIOClient from 'socket.io-client';
+
 import {
 	Replicant,
 	ReplicantOptions,

types/lib/replicant.d.ts

@@ -1,4 +1,5 @@
 import {EventEmitter} from 'events';
+import type * as SocketIOClient from 'socket.io-client'
 
 import {Logger} from './logger';
 import {Platform} from './platform';

types/typetest/package-lock.json

@@ -1,9 +1,8 @@
 {
   "private": true,
   "name": "fake-bundle",
-  "dependencies": {},
   "devDependencies": {
-    "typescript": "^3.1.3"
+    "typescript": "^4.3.5"
   },
   "scripts": {
     "build": "tsc --build src/dashboard src/extension"