Bug 2226646

#Issue

After the KDE Plasma Workspaces environment group has been installed (Fedora 38, x86_64), the following bugs occur when using the built in Maliit virtual keyboard:

* Post-login lockscreens cannot access virtual keyboard (only the initial sddm login screen has access).

* The keyboard does not pop up for text input areas automatically.

* If plasma-mobile is installed alongside the KDE Plasma Workspaces environment group, the mobile environment will suffer the two bugs listed above.

* The keyboard can be manually toggled on from the panel, but cannot be toggled off from the panel.

# Cause
This is happening because the KDE Plasma Workspaces environment group installs the Input Methods group. That group contains a package called imsettings-plasma, which includes a file: /etc/xdg/plasma-workspace/env/xinput.sh. In that file, there are two functions imported and called from another file: /usr/libexec/imsettings-functions. Those functions are as follows:

```
function setup_gtk_immodule() {
    if is_imsettings_enabled && is_gtk_supported; then
    # Ensure GTK_IM_MODULE is empty. otherwise GTK+ doesn't pick up immodule through XSETTINGS
    unset GTK_IM_MODULE
    export GTK_IM_MODULE
    else
    [ -n "$GTK_IM_MODULE" ] && export GTK_IM_MODULE
    fi
}

function setup_qt_immodule() {
    if is_imsettings_enabled && is_qt_supported; then
    # FIXME: Qt doesn't support XSETTINGS for immodule yet.
    #        We still need to go with the older way.
    [ -n "$QT_IM_MODULE" ] && export QT_IM_MODULE
    else
    [ -n "$QT_IM_MODULE" ] && export QT_IM_MODULE
    fi
}
```

The first function sets GTK_IM_MODULE to a non-null value, which prevents post-login lockscreens from having access to the virtual keyboard.

The second function is setting QT_IM_MODULE to a non-null value, which prevents the keyboard from popping up for text input areas, and from disappearing otherwise.

# Current workaround
Update the respective functions above to unset, the GTK_IM_MODULE and QT_IM_MODULE, regardless of the conditional logic. If those values are null, the Maliit keyboard works as intended for all use cases I listed previously.

Reproducible: Always

Steps to Reproduce:
1. Run `dnf group install "Input Methods" (should have happened automatically when distro was installed). Restart if Input Methods was not already installed
2. Use sddm to log into plasma desktop or plasma mobile
3. Enable Maliit keyboard. Toggle it on and off. 
4. Go to lock screen. Try to login with touch keyboard / click keyboard symbol. The keyboard won't pop up.
Actual Results:  
In step 3, Maliit won't toggle off in plasma desktop, and requires manual toggle on and off in plasma mobile.

In step 4- The virtual keyboard won't pop up - a physical keyboard must be used.

Expected Results:  
In step 3 - the keyboard should pop up automatically for text input areas, and disappear when a user selects a non text input area.

In step 4 - The keyboard should pop up automatically for touch, or optionally by clicking the keyboard symbol.

This has been cross posted in the Fedora KDE SIG issues tracker: https://pagure.io/fedora-kde/SIG/issue/371

Also, in plasma mobile, I believe that the keyboard symbol that is available in the upper right corner of the screen is a workaround for X11 applications. For instance, if you install the Slack flatpak, that keyboard symbol is the only way to use Maliit within the application, since it is X11. Automatic input only works for Wayland apps. I think something about the xinput.sh variables I listed in the cause section may be triggering X11 mode under all circumstances, but that's just a guess.