chore: log subscription issues on warn only if we are down to last pubsub provider

[thlorenz]

We encountered multiple warnings logged everytime a single provider tried to resub.
We log every 100th failure on warn, but should log on info if we still have a sufficient number of other pubsub providers properly connected.

We need to decide if we require at least one websocket connection or if a gRPC with historical feature is sufficient.