Fix state event visiblity in timeline

Rework the filtering of state events in the timeline and for lastevent. This is now consistent everywhere and includes the following:
- The timeline settings are obeyed everywhere
- A new setting is added to filter all state events
- Last event obeys the timeline setting in all cases
- The roomlist will show a state event as the latest event if it's visible in the timeline
- Names are no longer hyperlinked in eventToString if plaintext is selected.

BUG: 455048\
Closes network/neochat#148

src/neochatroom.h

@@ -131,7 +131,7 @@ public:
     /// This function respect the showLeaveJoinEvent setting and discard
     /// other not interesting events. This function can return an empty pointer
     /// when the room is empty of RoomMessageEvent.
-    [[nodiscard]] const Quotient::RoomEvent *lastEvent(bool ignoreStateEvent = false) const;
+    [[nodiscard]] const Quotient::RoomEvent *lastEvent() const;
 
     /// Convenient way to get the last event but in a string format.
     ///