text: Title: Add warning when the user launches Autokey under wayland
  Body: Just to ease issues with users not understanding what is going wrong.
  
  If this could be tagged as easy fix that would be neat.
  
  So if anyone wants to take a crack at fixing this here is what more or less how I would do it;
  
  https://unix.stackexchange.com/questions/202891/how-to-know-whether-wayland-or-x11-is-being-used
  From this link, the command `loginctl show-session $(awk '/tty/ {print $1}' <(loginctl)) -p Type | awk -F= '{print $2}'` seems to be the best solution to determine what login session the user is in. (`wayland` or `x11`)
  
  I'd slap this in a function in `UI_common_functions.py` with a `subprocess` call (there are many examples of using this call elsewhere in the codebase) and check the output and throw both a logging message as well as an error message (I'd add it in the `checkRequirements()` function in the same file.
    