Fix drawing custom colours for wxEnumProperty choice items in wxPG.

In order to draw choice items with custom colours there is necessary to merge custom cell object (wxPGCell) associated with individual item with default cell object (in wxPGProperty::GetDisplayInfo).
wxPGProperty::GetDisplayInfo function should return customized cell object instead of returning pointer to the default cell object only.

Closes #16509

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77505 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/propgrid/property.h

@@ -2298,11 +2298,20 @@ public:
     wxPGProperty* GetPropertyByName( const wxString& name ) const;
 
     // Returns various display-related information for given column
+#ifdef WXWIN_COMPATIBILITY_3_0
+    wxDEPRECATED_MSG("don't use GetDisplayInfo function with argument of 'const wxPGCell**' type. Use 'wxPGCell*' argument instead")
     void GetDisplayInfo( unsigned int column,
                          int choiceIndex,
                          int flags,
                          wxString* pString,
                          const wxPGCell** pCell );
+#endif //  WXWIN_COMPATIBILITY_3_0
+    // This function can return modfied (customized) cell object.
+    void GetDisplayInfo( unsigned int column,
+                         int choiceIndex,
+                         int flags,
+                         wxString* pString,
+                         wxPGCell* pCell );
 
     static wxString*            sm_wxPG_LABEL;