Set mouse cursor correctly over image map links in wxHTML.

The cursor didn't change to a link one when the mouse was over link areas in
an image map.

Fix this by generalizing wxHtmlCell::GetMouseCursor() into GetMouseCursorAt().

Closes #15350.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74570 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/html/htmlcell.h

@@ -319,9 +319,25 @@ public:
 
         @param window
             interface to the parent HTML window
+
+        @see GetMouseCursorAt()
     */
     virtual wxCursor GetMouseCursor(wxHtmlWindowInterface* window) const;
 
+    /**
+        Returns cursor to show when mouse pointer is over the specified point.
+
+        This function should be overridden instead of GetMouseCursorAt() if
+        the cursor should depend on the exact position of the mouse in the
+        window.
+
+        @param window
+            interface to the parent HTML window
+
+        @since 3.0
+     */
+    virtual wxCursor GetMouseCursorAt(wxHtmlWindowInterface* window) const;
+
     /**
         Returns pointer to the next cell in list (see htmlcell.h if you're
         interested in details).