Add timeouts for topology metadata fetch

[wprzytula]

At the moment, the driver never timeouts a metadata fetch attempt. If the server hangs on application level (but still keeps TCP connections alive), the driver will never go on to try fetching metadata from another node. We should add timeouts for that, and probably a configuration option in SessionConfig for that.

[Lorak-mmk]

Should we close that in favor of #1052 ? @wprzytula

[wprzytula]

Should we close that in favor of #1052 ? @wprzytula

IIUC, #1052 is about setting custom server-side timeouts, whereas this issue is about driver-side timeouts.