ui/key: rename ChordEvent to just Event

Event is like pointer.Event and we don't want the stuttering of
key.KeyEvent.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/app/os_windows.go

@@ -269,7 +269,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		return 1
 	case _WM_KEYDOWN, _WM_SYSKEYDOWN:
 		if n, ok := convertKeyCode(wParam); ok {
-			cmd := key.ChordEvent{Name: n}
+			cmd := key.Event{Name: n}
 			if getKeyState(_VK_CONTROL)&0x1000 != 0 {
 				cmd.Modifiers |= key.ModCommand
 			}