KWin's Desktop Effects suffer from the following UI issues:
- Inappropriate use of the word "Desktop." In the typical user's understanding, the desktop is the thing with a wallpaper and icons on it.
- Inconsistent terminology: mostly called "desktop effects", but the string "Window manager effects" is used in knsrc
- Inconsistent terminology between the KCM name, comment, and title
This patch resolves all three issues by using the more accurate term "Graphical Effects", and using it consistently, with appropriate sentence-style tooltips.
Because KWin maintainers have indicated in D14561 that in circumstances like this, all instances of a string should be changed, I have changed the string in the backend as well, not only for the user interface.