OutputDevice: mark them as disabled initially
This is needed so that libkScreen is able to transmit screen enablement outputDevice when sending screen update requests in WaylandConfig::applyConfig because WaylandOutput::setWlConfig won't notice a screen being activated by Kscreen
KScreen::Output::isEnabled is initially set in WaylandOutput::updateKScreenOutput to m_device->enabled() == Wl::OutputDevice::Enablement::Enabled