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/providers/twitch/TwitchMessageBuilder.hpp

@@ -68,6 +68,10 @@ public:
                                          Channel *channel,
                                          MessageBuilder *builder);
 
+    // Shares some common logic from SharedMessageBuilder::parseBadgeTag
+    static std::unordered_map<QString, QString> parseBadgeInfoTag(
+        const QVariantMap &tags);
+
 private:
     void parseUsernameColor() override;
     void parseUsername() override;