CE-108 Move ImageReview classification logic away from Perl script

DO NOT MERGE

See also: https://github.com/Wikia/backend/pull/92
These are assigned for MEDIATYPE_BITMAP and MEDIATYPE_DRAWING in the [setMediaType](https://github.com/Wikia/app/blob/dev/extensions/wikia/Scribe/ScribeEventProducer.class.php#L331-L341) method.