Fixed splits losing filters when closing and reopening them (#3351)

Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/widgets/splits/ClosedSplits.hpp

@@ -3,6 +3,7 @@
 #include "common/Channel.hpp"
 #include "widgets/helper/NotebookTab.hpp"
 
+#include <QUuid>
 #include <deque>
 #include <mutex>
 #include <utility>
@@ -14,6 +15,7 @@ class ClosedSplits
 public:
     struct SplitInfo {
         QString channelName;
+        QList<QUuid> filters;
         NotebookTab *tab;  // non owning ptr
     };