bug#38213: 27.0.50; add tooltip move-frame handling to mouse-avoidance-mode

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Date: Fri, 15 Nov 2019 01:32:03 +0200
> 
> Some recent change caused tooltip frames to emit a new kind of event
> 'move-frame' (not sure should I try bisecting to find that commit)
> that forces the mouse pointer in mouse-avoidance-mode to move
> and thus removing the tooltip frame immediately after displaying it.
> 
> This patch adds handling of the new event 'move-frame':

Shouldn't we instead avoid emitting this event when a tooltip frame is
positioned?  Otherwise, we will have to make such adaptations in many
places.