Update the networkState RPC with the latest networking change

[tomaka]

First of all, we can now have multiple active connections to the same node, so the RPC query should be updated to show multiple addresses when that happens.

Additionally, we should also add a lot of things to this query: the list of notification streams open, the ongoing requests, and so on.
Tackling this issue consists in figuring out exactly what can be added, knowing that the point of this query is to show to humans what the current networking state is.

[bkchr]

Wasn't the idea to deprecate this RPC endpoint? Or was this a different one?

[tomaka]

Yeah, rename it: #558

Gav mentioned that he was looking at it from time to time, and it might indeed not be a bad idea to leave an RPC query for people to look at what their node is doing (as long as we're pretty clear on the fact that what is returned is unstable).

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.

[tomaka]

Issue still relevant and important.