Keep new socket option for "Unconnected Sockets" mode

When working with huge node groups, toggling with Ctrl+H "Unconnected Sockets" mode for nodes, especially group inputs with lots of sockets, becomes vital.

The problem is that as you build on these node groups and add new things, every time you need to connect a value to the group input/output, you have to turn on all unconnected sockets again, opening the huge node and go down to connect the value to a new socket.

PROPOSAL

Keep the option of connecting a value to a new socket even when the node is hiding unconnected sockets: the point of this feature is to hide sockets that we are not using, but shouldn't prevent the addition of new ones.