Move wrap function to windowbase so all windows can use it

apps/openmw/mwgui/race.cpp

@@ -23,16 +23,6 @@
 
 namespace
 {
-    int wrap(int index, int max)
-    {
-        if (index < 0)
-            return max - 1;
-        else if (index >= max)
-            return 0;
-        else
-            return index;
-    }
-
     bool sortRaces(const std::pair<ESM::RefId, std::string>& left, const std::pair<ESM::RefId, std::string>& right)
     {
         return left.second.compare(right.second) < 0;

apps/openmw/mwgui/windowbase.cpp

@@ -15,6 +15,16 @@
 
 using namespace MWGui;
 
+int MWGui::wrap(int index, int max)
+{
+    if (index < 0)
+        return max - 1;
+    else if (index >= max)
+        return 0;
+    else
+        return index;
+}
+
 WindowBase::WindowBase(std::string_view parLayout)
     : Layout(parLayout)
 {

apps/openmw/mwgui/windowbase.hpp

@@ -14,6 +14,8 @@ namespace MWGui
 {
     class DragAndDrop;
 
+    int wrap(int index, int max);
+
     struct ControllerButtonStr
     {
         std::string a;