Add information about the node to the `ConnectionPoolError` logs and/or type

[muzarski]

While investigating one of the integration tests of cpp-rust-driver, I noticed that rust-driver emits following log (when the test triggers connect timeout):

ERROR: message: Could not fetch metadata, error: Control connection pool error:
The pool is broken; Last connection failed with: Connect timeout elapsed

There is no information about the node associated with the pool. We should include it in the log message (which is emitted here).

Ideally, though, we should include this information along with the ConnectionPoolError. I'm not sure if this is doable without introducing breaking changes.