Add scripts for comprehensive benchmark TensorIterator

[zasdfgbnm]

🚀 Feature

Proposed in: #29743

TensorIterator is performance-critical but complicated. Changing some parts of it might
cause hard-to-realize regression on the other parts. It would be very convenient to have a script that benchmark all the case we could imagine:

Memory layout: trivial 1D, (contiguous dim, non-contiguous dims)
Problem size: small, medium, large
Type of computation: unary ops, binary ops, compare ops, reduction
Data type: all dtypes with/without promotion
Inplace: True, False
Device: CPU, CUDA

The designed usage of the script could be:

Step 1:
Install a PyTorch build of the master branch, and run

python main.py benchmark baseline.json

Step 2:
Go to your branch, build install and run

python main.py benchmark new.json

Step 3:
Run the following command to get the report:

python main.py compare baseline.json new.json report.html

cc: @ngimel @VitalyFedyunin
cc: @csarofeen

cc @VitalyFedyunin @ngimel @mruberry