Propagate model id used by Predictor to Caffe2 logging
Summary:
Does the same things as D19658565 but for Caffe2 models.
From investigation https://fb.quip.com/PbgsAEmoJVuf the model id that predictor uses and the model id saved inside the model don't match. Common reason is recurring fluent2 jobs but there are others.
Since model_id from predictor is what the rest of datasets use, it's way more useful imho. I've considered adding both ids, but it'd require additional piping and I don't think it's that useful.
Test Plan: unittests added
Reviewed By: houseroad
Differential Revision: D20630599
fbshipit-source-id: 3e6d0cb0b6f8c8b6ae5935138f55ae7a2ff60653
