Create NeochatRoomMember as a shim for RoomMember

The intention is that NeochatRoomMember can be created passed to QML and then be fully managed by it. It effectively just grabs the current RoomMember, calls the correct function then discards it so that we don't end up trying to access an already deleted state event.

src/neochatroom.cpp

@@ -1767,6 +1767,11 @@ const RoomEvent *NeoChatRoom::getEvent(const QString &eventId) const
         return timelineIt->get();
     }
 
+    const auto pendingIt = findPendingEvent(eventId);
+    if (pendingIt != pendingEvents().end()) {
+        return pendingIt->event();
+    }
+
     auto extraIt = std::find_if(m_extraEvents.begin(), m_extraEvents.end(), [eventId](const Quotient::event_ptr_tt<Quotient::RoomEvent> &event) {
         return event->id() == eventId;
     });