[Feature Request] Security: Implement Picklescan

[iwr-redmond]

Picklescan is a simple package to scan legacy Checkpoints and TIs for suspicious code. It has previously been implemented in EasyDiffusion (see ui/easydiffusion/model_manager.py#354).

Please incorporate this package into stablepy, and scan pickletensor files before they are cleared for inference. As the code for EasyDiffusion's backend sdkit shows, the implementation is very easy.