refactor: add missing .js extension for ESM usage

Author: darrachequesne

lib/index.ts

@@ -6,4 +6,4 @@ export const protocol = Socket.protocol;
 export { Transport } from "./transport.js";
 export { transports } from "./transports/index.js";
 export { installTimerFunctions } from "./util.js";
-export { parse } from "./contrib/parseuri";
+export { parse } from "./contrib/parseuri.js";

lib/socket.ts

@@ -5,7 +5,7 @@ import { parse } from "./contrib/parseuri.js";
 import debugModule from "debug"; // debug()
 import { Emitter } from "@socket.io/component-emitter";
 import { protocol } from "engine.io-parser";
-import { CloseDetails } from "./transport";
+import { CloseDetails } from "./transport.js";
 
 const debug = debugModule("engine.io-client:socket"); // debug()