HUE-5719 [notebook] Recheck status when received status "waiting" (#475)
* Added new check for the status waiting
New response from Livy-server that the job can be in a waiting state, see commit LIVY-213 https://github.com/cloudera/livy/commit/b4642b193956b287bb1c1b32bafe4c5a15e71eac
* Minor formatting change to previous commit