x11integration: Force standalone Qt::Dialog resizable
Because KWin now honors minimize/maximize button hint.
- can minimize and maximize KFind again
- can minimize and maximize Spectacle again
- file properties dialog in Dolphin remains non-minimizable because it doesn't have its own task bar entry so it would be inaccessible (which is probably the rationale for why dialog does that in the first place)
Edited by Kai Uwe Broulik