CE-1125 ImageReview fixes continuation

This commit includes:
* Improved isLocalFile check
* Task clearing the queue from rows that it can't create a GlobalTitle object for
* Removal of Invalid queue
* Logging of every action (see [Kibana dashboard](https://kibana.wikia-inc.com/#/dashboard/elasticsearch/ImageReview%20Logs))
* More refactoring
* More documentation

Pinging @macbre @Grunny 
Can we log failed deletions as well?