Add C++ torch::nn::functional::affine_grid (#27263)
Summary:
Adds`torch::nn::functional::affine_grid` functional support for the C++ API.
Issue: https://github.com/pytorch/pytorch/issues/25883, https://github.com/pytorch/pytorch/issues/27196
Reviewer: yf225
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27263
Differential Revision: D17802350
Pulled By: yf225
fbshipit-source-id: e823ee53da4a4cc6a1650d2dfc09b0ef6a74e249
