Ask the user whether they want to quit, instead of close the window

[Duha]

@johnandmegh

. I’m sure “restore closed window for Dolphin” would be very non-trivial to implement, but I’m also sure that it has a lower chance of ever happening if there’s no formal feature request!

Is this setting not good enough?

If you accidentally close a dolphin window, just restart it and it shows with all tabs and split view settings from just closed tab.