Bind subgraph newAbortController event to parent graph

[ZhangYiJiang]

Using --trace-warnings I think the warning is still happening because of subgraphs - the event is only bound in createProcessor, but the trace shows the call stack going through SubGraphNodeImpl and createSubProcessor does not bind this event so the controllers aren't passed back up.

[abrenneke]

So, I'm really not sure if this was intentional or not :/

[ZhangYiJiang]

Pretty sure it's not intended since this means the original code that tried to suppress the event emitter warnings just didn't work if you used any subgraphs.

The original code had to pass the controller through events because the controllers were created in iso code and could not call setMaxListeners since that's a Node API (there is nodejs/node#54758 but it was not adopted), it's not really a meaningful event, it's just a workaround to allow rivet-core to remain isomorphic

[abrenneke]

Oh right, yeah!