Fix #110821: Tracker resizing with S+S also resizes search area

Regression caused by 03f17c42d0

In that commit it was assumed that the hotkey modifier `S` had no
influence if we were already resizing.

But this is not the case in tracking. The second `S` has influence and
should not be filtered.

The solution is to add a conditional only to Trackers transformation.

This commit also fixed the canceling of this transformation which did
not revert the search area to its original value.

source/blender/editors/transform/transform.cc

@@ -650,7 +650,9 @@ static bool transform_modal_item_poll(const wmOperator *op, int value)
         return false;
       }
       if (value == TFM_MODAL_RESIZE && t->mode == TFM_RESIZE) {
-        return false;
+        /* The tracking transform in MovieClip has an alternate resize that only affects the
+         * tracker size and not the search area. */
+        return t->data_type == &TransConvertType_Tracking;
       }
       if (value == TFM_MODAL_VERT_EDGE_SLIDE &&
           (t->data_type != &TransConvertType_Mesh ||

source/blender/editors/transform/transform_convert_tracking.cc

@@ -481,7 +481,7 @@ static void flushTransTracking(TransInfo *t)
 
       if (t->flag & T_ALT_TRANSFORM) {
         if (t->mode == TFM_RESIZE) {
-          if (tdt->area != TRACK_AREA_PAT) {
+          if (tdt->area != TRACK_AREA_PAT && !(t->state == TRANS_CANCEL)) {
             continue;
           }
         }