Retry logic for failed subscriptions after reconnect

[jbarlow-mcafee]

Currently, the on_connect_run logic in the client attempts to resubscribe for all previously subscribed topics when a reconnect occurs. This logic happens here. If any subscriptions were to fail, the current logic just writes out an error to the console but does not retry the attempt at a later time. This could leave the client in a state where some subscriptions are unexpectedly not active until / unless the client happens to reconnect again. There should be some additional logic added to retry the failed subscriptions - perhaps by triggering the full disconnect / reconnect sequence up to the number of connect retries which have been configured.