Currently, touchpad X11 supports 3 different backends: evdev, synaptics, libinput. However touchpad Wayland only need libinput. Currently, they all mixed and this makes the KCM complex.
At the end of this patch, Touchpad KCM will be splitted into 2 different KCMs; kcm_touchpad (Wayland), kcm_touchpadx (X11)

This patch aims to followings;
1- The future is Wayland + Libinput so having a seperated KCM for it makes the development easier and gives the flexibility to the developer. This leads to more stability.
2- KCMs should be converted to KConfigModule and at the end of the patch, KDE'll have a simple Wayland + Libinput KCM in KConfigModule.
3- touchpadX will be simpler too thanks to cleaning.

The need to this patch is occured when I'm trying to bring the touchpad libinput KCM support to X. Current complexity makes the development really confusing and that means bug. So after this patch, the work for touchpad libinput KCM support will be done.

The current patch strategy is as following:
Stage 1- Renaming current kcm_touchpad as kcm_touchpadx and moving them to the new folder called "touchpadx". Then creating a dummy touchpad in "touchpad" folder which will be kcm_touchpad that will only work in Wayland.
Expected test result: In Wayland, there are 2 Touchpad KCMs, kcm_touchpad which is the dummy Wayland-only KCM and kcm_touchpadx which is the old one with a new name. In X11, there is only kcm_touchpadx.

Stage 2- Remove everything about Wayland in kcm_touchpadx. Make some cleaning. After this patch, X11 related work should be finished at all.
Expected test result: In Wayland, there is only kcm_touchpad which is the dummy Wayland-only KCM. In X11, there is a X11-only, fully functional kcm_touchpadx.

Stage 3- Write Wayland Touchpad KCM in KConfigModule.
Expected test result: Wayland has kcm_touchpad, X11 has kcm_touchpadx. Both working fine. Everything should be working at this point.

Future Patch- Libinput KCM support to X11!

Stage 1 Patch : In progress..
Stage 2 Patch : ToDo
Stage 3 Patch : ToDo

OLD PATCHES
Stage 1 Patch : D13997 Removing Wayland Part of Touchpad KCM
Stage 2 Patch : D14016 Files in "touchpad" Moved To The New Folder "touchpadx"
Stage 3 Patch : D14017 Dummy Wayland Touchpad KCM is Created in "touchpad" Folder