universal-access: Add "Locate Pointer" option
Since [0] and [1], "locate pointer" is now in Mutter and works well under Wayland and X11.
Once activated, the mouse pointer can be located on the screen by pressing the Ctrl key. Pressing Ctrl will cause an animation to appear briefly at the location of your pointer.
Fixes #586 (closed)
This implementation adds a row called "Locate Pointer" to the "Pointing & Clicking" section of the Universal Access panel. The "Locate Pointer" label is not very clear about what it does. In the past the string was "Show position of pointer when the Control key is pressed", which is much clearer on the functionality but significantly longer than all the other rows (Mouse Keys, Click Assist, Double-CLick Delay). Is there a better sentence to go with or a tooltip we could use to clarify the feature? cc @aday