Un-pin torch version

Summary:
We released the restriction of torch version due to the version requirement conflicts with ax package.
We also removed some redundant code due to the removal of neural prophet model

Reviewed By: yangbk560

Differential Revision: D34878121

fbshipit-source-id: 1878e81b338164f16c3e180b899507f928632177

Detector Param Tuning

Summary: Minor changes to support metalearning for detection

Reviewed By: yangbk560

Differential Revision: D28313594

fbshipit-source-id: 9e21ed88b40ed4a9153508a9548652a0638903b9