Treat links as a single character for the purposes of delete, backspace, left and right.

When backspacing at a link the first key selects the whole link the second deletes. Similar for delete, left and right.

src/libneochat/chattextitemhelper.h

@@ -187,6 +187,11 @@ public:
      */
     void setCursorPosition(int pos);
 
+    /**
+     * @brief Set the selection of the underlying text item to the given cursor.
+     */
+    void setSelection(const QTextCursor &cursor);
+
     /**
      * @brief Set the cursor visibility of the underlying text item to the given value.
      */