Completely remove FutureMessage type (#50029)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/50029
Test Plan:
buck run mode/opt -c=python.package_style=inplace //caffe2/torch/fb/training_toolkit/examples:ctr_mbl_feed_april_2020 -- local-preset --flow-entitlement pytorch_ftw_gpu --secure-group oncall_pytorch_distributed
Before:
```
...
I0107 11:03:10.434000 3831111 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|total_examples 14000.0
I0107 11:03:10.434000 3831111 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|window_qps 74.60101318359375
I0107 11:03:10.434000 3831111 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|lifetime_qps 74.60101318359375
...
I0107 11:05:12.132000 3831111 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|total_examples 20000.0
I0107 11:05:12.132000 3831111 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|window_qps 64.0
I0107 11:05:12.132000 3831111 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|lifetime_qps 64.64917755126953
...
```
After:
```
...
I0107 11:53:03.858000 53693 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|total_examples 14000.0
I0107 11:53:03.858000 53693 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|window_qps 72.56404876708984
I0107 11:53:03.858000 53693 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|lifetime_qps 72.56404876708984
...
I0107 11:54:24.612000 53693 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|total_examples 20000.0
I0107 11:54:24.612000 53693 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|window_qps 73.07617950439453
I0107 11:54:24.612000 53693 print_publisher.py:23 master ] Publishing batch metrics: qps-qps|lifetime_qps 73.07617950439453
...
```
Reviewed By: lw
Differential Revision: D25774915
Pulled By: mrshenli
fbshipit-source-id: 1128c3c2df9d76e36beaf171557da86e82043eb9