text: Title: feature request : Batched scale_tril
  Body: I would like to do batch transformations using `transforms.LowerCholeskyAffine`. So far I can do a "batched" transform as long as the `loc` and `scale_tril` are the same however if I try to use different `loc`s with the same `scale_tril` then I get the following error message.
  >ValueError: Only support 2-dimensional scale_tril matrix. Please make a feature request if you need to use this transform with batched scale_tril.