Corrected the way we parse comma-separated "list tags" in PRIVMSGs (#3771)

tl;dr: we now split by slash only its first occurrence instead of every occurrence.

src/messages/Message.hpp

@@ -2,6 +2,7 @@
 
 #include "common/FlagsEnum.hpp"
 #include "providers/twitch/TwitchBadge.hpp"
+#include "util/QStringHash.hpp"
 #include "widgets/helper/ScrollbarHighlight.hpp"
 
 #include <QTime>
@@ -65,7 +66,7 @@ struct Message : boost::noncopyable {
     QColor usernameColor;
     QDateTime serverReceivedTime;
     std::vector<Badge> badges;
-    std::map<QString, QString> badgeInfos;
+    std::unordered_map<QString, QString> badgeInfos;
     std::shared_ptr<QColor> highlightColor;
     uint32_t count = 1;
     std::vector<std::unique_ptr<MessageElement>> elements;