[Game] Implement total power tally (#7057)

* [Game] Implement total power tally

* PR comments

cockatrice/src/game_graphics/tally/stats_tally.cpp

@@ -0,0 +1,36 @@
+#include "stats_tally.h"
+
+#include "../board/card_item.h"
+
+#include <QCoreApplication>
+#include <QList>
+#include <algorithm>
+
+static int sumPowers(const QList<CardItem *> &cards)
+{
+    // calculate total power;
+    int total = 0;
+    for (auto card : cards) {
+        QVariantList parsed = CardItem::parsePT(card->getPT());
+        if (!parsed.isEmpty()) {
+            int power = parsed.first().toInt(); // toInt will default to 0 if it's not an int
+            total += qMax(power, 0);
+        }
+    }
+    return total;
+}
+
+QList<TallyRow> StatsTally::computeTotalPower(const QList<CardItem *> &cards)
+{
+    // don't bother if none of the cards have pt
+    bool hasPT =
+        std::any_of(cards.cbegin(), cards.cend(), [](const CardItem *card) { return !card->getPT().isEmpty(); });
+    if (!hasPT) {
+        return {};
+    }
+
+    int total = sumPowers(cards);
+
+    QString name = QCoreApplication::translate("StatsTally", "Total Power");
+    return {TallyRow{name, QString::number(total)}};
+}