move: Use post input signal for touch move grabs (WayfireWM#2508)

Without this, touch fingers are not set yet which causes a visual jump
when attempting to move drag a window with touchscreen devices. Use
post signal so that the fingers are properly detected and the correct
coordinates are used in the first place.

Fixes WayfireWM#2505.

plugins/single_plugins/move.cpp

@@ -144,8 +144,8 @@ class wayfire_move : public wf::per_output_plugin_instance_t,
         }
     };
 
-    wf::signal::connection_t<wf::input_event_signal<wlr_touch_down_event>> on_raw_touch_down =
-        [=] (wf::input_event_signal<wlr_touch_down_event> *ev)
+    wf::signal::connection_t<wf::post_input_event_signal<wlr_touch_down_event>> on_raw_touch_down =
+        [=] (wf::post_input_event_signal<wlr_touch_down_event> *ev)
     {
         if (ev->event->touch_id == 0)
         {