Add info to shortcut settings for dropdown terminal under wayland

[stefonarch]

Expected Behavior

GUI should work or give information

Current Behavior

Shortcut settings applies only to X11 and has no effect under wayland.

Possible Solution

Add a similar note as done for power keys in lxqt-config-powermanagement:

 if (QGuiApplication::platformName() == QStringLiteral("wayland"))
    {
        mUi->waylandLabel->setText(tr("Note: Under Wayland a shortcut for "qterminal -d" has to be configured in the compositor instead. "));
    }

Not sure if also add an info about dialog windows appearing below.

System Information

• QTerminal version: all

[tsujan]

Yes, I noticed it too, among other small problems, when testing https://github.com/lxqt/qterminal/pull/1146.

[stefonarch]

Done in https://github.com/lxqt/qterminal/pull/1151