[quant][graphmode][fx] Support sigmoid/hardsigmoid/tanh in qat (#46738)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/46738
Test Plan: Imported from OSS
Reviewed By: raghuramank100
Differential Revision: D24486972
fbshipit-source-id: c9f139bfdd54973da1a93a45e32937595dbe67fc
