deploy-input-methods: Change wayland virtual keyboard provider to Fcitx

Fcitx is now the preferred input method, we should install it while keeping IBus as the fallback.

We should also switch to using the community.general.kdeconfig module as well.

Refer to Enable the File System Browser plugin of the Kate editor by default. task for the implementation.

Desktop file: /usr/share/applications/org.fcitx.Fcitx5.desktop