Make ShardedTensor ctor more inline with torch.Tensor ctor (#72164)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72164
torch.Tensor ctor creates an empty tensor and this PR makes
ShardedTensor on par with that.
In particular we remove TensorInitParams and instead always a create an empty
tensor and then fill it in for things like ones, zeros, full etc. This is
inline with torch.ones etc. as well since even for those APIs we first create
an empty tensor and then fill it out.
ghstack-source-id: 148318045
Test Plan: waitforbuildbot
Reviewed By: wanchaol
Differential Revision: D33934603
fbshipit-source-id: 5655bbd726f29e74600ebe9f33f9dc5952b528f4
(cherry picked from commit 78b301c78c9d5046e2f0a9818dcbc2cc45e7cdd0)
