move windows

Somehow, the Clipboard History window became moved to the very left edge of the screen, and since the title bar is not accessible - only the settings icon, but not the rest - i cannot move it back to be able to use it. How can I move the window to the right to make it usable again?

I use 3 monitors and like to have several full screen windows on each. I often want to move a window from one to another and it is tedious having to 1. exit full screen 2. show the desktop on the other display (so a window can be dropped onto it) 3. move window to another display 4...