Core/Movement: Add LOS check for fleeingmovement target point.

Prevents fleeing or feared units from going to upper floor ignoring walls/ceilings with mmaps on(and usually get stucked).

Current implementation just randomly selects a distance and angle against the frighting unit, when in narrow circumstance such as underground caves, such targeting point would be at another floor.

Closes #11300
Ref #9475 (needs fixed confirmation)

src/server/worldserver/Master.cpp

@@ -86,8 +86,8 @@ private:
     uint32 _lastChange;
     uint32 _delaytime;
 public:
-    FreezeDetectorRunnable() 
-    { 
+    FreezeDetectorRunnable()
+    {
         _loops = 0;
         _lastChange = 0;
         _delaytime = 0;