[Game] Refactor: move parsePT to a static method (#6860)

cockatrice/src/game/board/card_item.h

@@ -146,6 +146,26 @@ public:
     void drawAttachArrow();
     void playCard(bool faceDown);
 
+    /**
+     * @brief Parses a string representing a p/t in order to extract the values from it.
+     *
+     * If the string contains '/', the string will be split at the '/' and each side will be parsed separately,
+     * which means the result list will have two elements.
+     *
+     * If '/' is not found, then the entire string is parsed together, which means the result list will
+     * have a single element.
+     *
+     * If either side of the split is empty, there will also only be a single element in the result list.
+     *
+     * This function will attempt to parse each substring as an int first, handling plus and minus prefixes.
+     * If successful, it will put the parsed value into the QVariant as an int.
+     * If failed, it will just put the substring into the QVariant as a QString.
+     *
+     * @param pt The p/t string
+     * @return A QVariantList that can contain one or two elements, where each QVariant can be either int or QString
+     */
+    static QVariantList parsePT(const QString &pt);
+
 protected:
     void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override;
     void mouseReleaseEvent(QGraphicsSceneMouseEvent *event) override;