Segment RTCs are recorded in the segment edit history, allowing editors to easily check along a route to see if a now-expired closure may have been the reason for a routing problem flagged up via a UR.

Now that we have the ability to also mark nodes as open/closed in order to allow/deny routing across a closure, having node closure states recorded in the history is also important, so that we can deal with URs related to routing problems along those cross routes as well.

ideally we'd be able to see in the history for a given segment if either of its nodes had been marked as closed (and over what period of time the closure was active), even if the node closure had been implemented as part of a RTC set up on a different segment.