…2681)

Brunt of the work for pytorch/pytorch#93991

Changes:
1. Adds a script (`binary_size_validation.py `) to perform wheel size
fetching and validation using given rules.
2. Includes the specific job pattern from the builder repo to create
alerts.
3. Fixes a minor bug in `check_alerts.py` (regression from #2109)

A separate PR will schedule the script periodic execution in the
pytorch/builder repo (TODO). The builder repo is chosen as compromise,
as `test-infra` doesn't have HUD enabled as of now (alerts do not work).


----

### Brief docs for `binary_size_validation.py ` (separate readme is
included):

#### Installation

```bash
pip install -r requirements.txt
```

#### Usage
    
```bash
# print help
python binary_size_validation.py --help

# print sizes of the all items in the index
python binary_size_validation.py --url https://download.pytorch.org/whl/nightly/torch/

# fail if any of the torch2.0 wheels are larger than 900MB
python binary_size_validation.py --url https://download.pytorch.org/whl/nightly/torch/ --include "torch-2\.0"  --threshold 900

# fail if any of the latest nightly pypi wheels are larger than 750MB
python binary_size_validation.py --include "pypi" --only-latest-version --threshold 750
```