Fix: Exit http server on php exit (#1714)

## Motivation for the change, related issues
Calling the `php.exit` caused a hanging connection. This had affect in
tests, and leaving open connections around.
## Implementation details
Attach the HTTP server that we spawn to handle websocket connections to
the PHP instance.
When we call `.exit` we use the attached instance to close the
connections.

## Testing Instructions (or ideally a Blueprint)
1. Create a project with the following test code:

```import { getPHPLoaderModule, withNetworking } from '@php-wasm/node';
import { PHP, __private__dont__use, loadPHPRuntime } from '@php-wasm/universal';

const isWindows = process.platform === 'win32';

const dostuff = async function() {
	const id =  await loadPHPRuntime(
		await getPHPLoaderModule('8.3'),
		await withNetworking({})
	);
	const php = new PHP(id);

	const privateSymbol = Object.getOwnPropertySymbols(php)
		.find(sym => String(sym).includes('__private__dont__use'));


	const result = await php.run({ code: `<?php echo "HI!"; `} );
	console.log(result.text);
	php.exit();

}

dostuff().catch(console.error);
```
2. Build `php-wasm/node` and `php-wasm/universal`

```
npx nx run php-wasm-universal:build
npx nx run php-wasm-node:build
```
4. Cd into `/dist` php-wasm folder and run `npm link`
5. Go to the project and run `npm link @php-wasm/node` and `npm link
@php-wam/universal`
6. Navigate inside node module, in each package and run `npm install`
7. Run the script you have created
8. Ensure that exits successfully

packages/php-wasm/node/src/lib/networking/with-networking.ts

@@ -12,10 +12,13 @@ export async function withNetworking(
 	const [inboundProxyWsServerPort, outboundProxyWsServerPort] =
 		await findFreePorts(2);
 
-	await initOutboundWebsocketProxyServer(outboundProxyWsServerPort);
+	const outboundNetworkProxyServer = await initOutboundWebsocketProxyServer(
+		outboundProxyWsServerPort
+	);
 
 	return {
 		...phpModuleArgs,
+		outboundNetworkProxyServer,
 		websocket: {
 			...(phpModuleArgs['websocket'] || {}),
 			url: (_: any, host: string, port: string) => {

packages/php-wasm/node/src/test/php-networking.spec.ts

@@ -2,10 +2,12 @@ import {
 	PHP,
 	SupportedPHPVersions,
 	setPhpIniEntries,
+	getLoadedRuntime,
 } from '@php-wasm/universal';
 import express from 'express';
 import { rootCertificates } from 'tls';
 import { loadNodeRuntime } from '../lib';
+import http from 'http';
 
 describe.each(SupportedPHPVersions)(
 	'PHP %s',
@@ -169,6 +171,27 @@ describe.each(SupportedPHPVersions)(
 				console.log(text);
 				expect(text).toContain('bool(true)');
 			});
+
+			it('should close server when runtime is exited', async () => {
+				const id = await loadNodeRuntime(phpVersion);
+				const php = new PHP(id);
+				const rt = getLoadedRuntime(id);
+
+				expect(rt.outboundNetworkProxyServer).toBeDefined();
+				expect(rt.outboundNetworkProxyServer).toBeInstanceOf(
+					http.Server
+				);
+
+				expect(rt.outboundNetworkProxyServer.listening).toBe(true);
+				php.exit();
+
+				// Wait for the server to close
+				await new Promise((resolve) => {
+					rt.outboundNetworkProxyServer.on('close', resolve);
+				});
+
+				expect(rt.outboundNetworkProxyServer.listening).toBe(false);
+			});
 		});
 	},
 	1000

packages/php-wasm/universal/src/lib/index.ts

@@ -48,7 +48,7 @@ export type {
 } from './supported-php-extensions';
 export { PHP, __private__dont__use } from './php';
 export type { MountHandler, UnmountFunction } from './php';
-export { loadPHPRuntime } from './load-php-runtime';
+export { loadPHPRuntime, getLoadedRuntime } from './load-php-runtime';
 export type * from './emscripten-types';
 export type {
 	DataModule,

packages/php-wasm/universal/src/lib/load-php-runtime.ts

@@ -1,4 +1,5 @@
 import { logger } from '@php-wasm/logger';
+import { IncomingMessage, Server, ServerResponse } from 'http';
 
 const RuntimeId = Symbol('RuntimeId');
 const loadedRuntimes: Map<number, PHPRuntime> = new Map();
@@ -160,6 +161,10 @@ export async function loadPHPRuntime(
 	PHPRuntime.originalExit = PHPRuntime._exit;
 
 	PHPRuntime._exit = function (code: number) {
+		if (PHPRuntime.outboundNetworkProxyServer) {
+			PHPRuntime.outboundNetworkProxyServer.close();
+			PHPRuntime.outboundNetworkProxyServer.closeAllConnections();
+		}
 		loadedRuntimes.delete(id);
 		return PHPRuntime.originalExit(code);
 	};
@@ -238,6 +243,10 @@ export type EmscriptenOptions = {
 	onRuntimeInitialized?: () => void;
 	monitorRunDependencies?: (left: number) => void;
 	onMessage?: (listener: EmscriptenMessageListener) => void;
+	outboundNetworkProxyServer?: Server<
+		typeof IncomingMessage,
+		typeof ServerResponse
+	>;
 	instantiateWasm?: (
 		info: WebAssembly.Imports,
 		receiveInstance: (