Move cauchy_() to DistributionTemplates (#37602)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37602
Fixes #37371
Test Plan: Imported from OSS
Differential Revision: D21334739
Pulled By: pbelevich
fbshipit-source-id: b8443c14760ec825da3f7d300ad496578170671f
