Deprecate torch::nn::modules_ordered_dict API (#28774)
Summary:
I finally found a way to get the following API to work for constructing a list of named submodules for `Sequential`:
```cpp
Sequential sequential({
{"m1", MyModule(1)},
{"m2", MyModule(2)}
})`
```
which was actually our original proposed design and much simpler than our current API:
```cpp
Sequential sequential(modules_ordered_dict({
{"m1", MyModule(1)},
{"m2", MyModule(2)}
}));
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28774
Differential Revision: D18174013
Pulled By: yf225
fbshipit-source-id: 3a18c2d36b6a65a07bee7346a7516780567c7774
