Foldable State Events

Implement folding sections for multiple consecutive state events. This also reworks some of the aggregated text output:

- Only new days cause a new section
- The aggregated text starts with either a single username or n users
- If the same user did the same action mutltiple times it will be in the aggregated text a user did x n times
- When there are multiple authors in a block with multiple state event types it will use or rather than and before the last event. e.g 3 user left the room or joined the room.

Folded

![image](/uploads/17141ed5e1f2e0e3539523a082275976/image.png)

Unfolded

![image](/uploads/1d5db5804da457b921544cc81099997d/image.png)

Implements network/neochat#90

src/models/collapsestateproxymodel.h

@@ -12,10 +12,29 @@ class CollapseStateProxyModel : public QSortFilterProxyModel
 public:
     enum Roles {
         AggregateDisplayRole = MessageEventModel::LastRole + 1,
+        StateEventsRole,
+        AuthorListRole,
     };
     [[nodiscard]] bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const override;
     [[nodiscard]] QHash<int, QByteArray> roleNames() const override;
     [[nodiscard]] QVariant data(const QModelIndex &idx, int role = Qt::DisplayRole) const override;
 
+    /**
+     * @brief QString aggregating the text of consecutive state events starting at row.
+     *
+     * If state events happen on different days they will be split into two aggregate
+     * events.
+     */
     [[nodiscard]] QString aggregateEventToString(int row) const;
+    /**
+     * @brief Return a list of consecutive state events starting at row.
+     *
+     * If state events happen on different days they will be split into two aggregate
+     * events.
+     */
+    [[nodiscard]] QVariantList stateEventsList(int row) const;
+    /**
+     * @brief List of unique authors for the aggregate state events starting at row.
+     */
+    [[nodiscard]] QVariantList authorList(int row) const;
 };