Clarifies cholesky_ex role and makes batched support a common string (#58217)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/34272
Also updates and creates a common string for when the linear algebra operations support batching
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58217
Reviewed By: ngimel
Differential Revision: D28405908
Pulled By: mruberry
fbshipit-source-id: a9d81a5a4712cfdedc22d614986d3707f10742a2
