[quant][graphmode][refactor] Better API for fold_convbn (#32380)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32380
We'll clone the module first and then fold conv bn and return a new
module
Test Plan:
.
Imported from OSS
Differential Revision: D19508033
fbshipit-source-id: 328e91a2c9420761c904a7f2b62dab4cfaaa31ac
