Add more inplace arguments to quantization top level API (#26782)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26782
At least we should be consistent on top-level APIs and prepare/convert/etc.
Logic is inplace=False by default but top-level APIs take care of doing fewer copies.
Also renames always-inplace methods like add_observer to have underscore in the end.
One fix for MinMaxObserver was triggered by deepcopy surfacing that we were accidentally keeping autograd around
Test Plan: Imported from OSS
Differential Revision: D17595956
Pulled By: dzhulgakov
fbshipit-source-id: 801f9f5536b553f24c7a660064dd6fce685edd65
