Revert "[quant][pt2e][bc-breaking] Remove fold_quantize flag (#118701)"
This reverts commit 482d952e880cf78c103a06f2d483556ab0a89138.
Reverted https://github.com/pytorch/pytorch/pull/118701 on behalf of https://github.com/facebook-github-bot due to Diff reverted internally ([comment](https://github.com/pytorch/pytorch/pull/118701#issuecomment-1932866964))
