feat(utils): add hashing a checkpoint utility

[ydcjeff]

fix #2269

Description: Add hashing utility for checkpoint

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

@ydcjeff thanks for the PR ! First of all, mypy is not passing on it. I'm hesitating on adding the cmd line tool. I see the benefit but not sure if ignite should provide cmd line tools for the moment. @sdesrozis @trsvchn thoughts ?

[sdesrozis]

@ydcjeff Thanks for this feature !

The hash_checkpoint looks good and can be used as we prefer, that's great. Although I'm not sure about providing a cmdline tool... I would rather have this as a checkpointing option even if it seems not so simple according to loggers, etc.

[ydcjeff]

I'm hesitating on adding the cmd line tool.

@vfdev-5 If we are not sure about CLI, we could add it in the future.

I would rather have this as a checkpointing option even if it seems not so simple according to loggers, etc.

@sdesrozis As I stated in the issue, I believe this function is mostly used for the finalized checkpoint, so I am not sure adding another argument in the Checkpoint class which could add read/write overhead if used.

[vfdev-5]

If we are not sure about for CLI, we could add it in the future.

@ydcjeff sounds good, let's scope this PR for python utils method.

[vfdev-5]

LGTM, thanks @ydcjeff