Enhance socket cleanup and management for improved connection handling

- Refactor cleanupSocket function to support options for immediate destruction, allowing drain, and grace periods.
- Introduce createIndependentSocketHandlers for better management of half-open connections between client and server sockets.
- Update various handlers (HTTP, HTTPS passthrough, HTTPS terminate) to utilize new cleanup and socket management functions.
- Implement custom timeout handling in socket setup to prevent immediate closure during keep-alive connections.
- Add tests for long-lived connections and half-open connection scenarios to ensure stability and reliability.
- Adjust connection manager to handle socket cleanup based on activity status, improving resource management.

ts/proxies/http-proxy/http-proxy.ts

@@ -520,9 +520,10 @@ export class HttpProxy implements IMetricsTracker {
     this.webSocketHandler.shutdown();
     
     // Close all tracked sockets
-    for (const socket of this.socketMap.getArray()) {
-      cleanupSocket(socket, 'http-proxy-stop');
-    }
+    const socketCleanupPromises = this.socketMap.getArray().map(socket => 
+      cleanupSocket(socket, 'http-proxy-stop', { immediate: true })
+    );
+    await Promise.all(socketCleanupPromises);
     
     // Close all connection pool connections
     this.connectionPool.closeAllConnections();