Kernel: Increase the default TCP window size

This increases the default TCP window size to a more reasonable
value of 64k. This allows TCP peers to send us more packets before
waiting for corresponding ACKs.

Kernel/Net/TCPSocket.cpp

@@ -174,7 +174,7 @@ KResult TCPSocket::send_tcp_packet(u16 flags, const UserOrKernelBuffer* payload,
     VERIFY(local_port());
     tcp_packet.set_source_port(local_port());
     tcp_packet.set_destination_port(peer_port());
-    tcp_packet.set_window_size(1024);
+    tcp_packet.set_window_size(NumericLimits<u16>::max());
     tcp_packet.set_sequence_number(m_sequence_number);
     tcp_packet.set_data_offset(sizeof(TCPPacket) / sizeof(u32));
     tcp_packet.set_flags(flags);