feature request: add pydantic.types.Sha256Str

[0num4]

Initial Checks

• [X] I have searched Google & GitHub for similar requests and couldn't find anything
• [X] I have read and followed the docs and still think this feature is missing

Description

If there is pydantic.types.Base64Str(), I think it would be reasonable to also have Sha256Str. What do you think?

Affected Components

• [ ] Compatibility between releases
• [ ] Data validation/parsing
• [ ] Data serialization - .model_dump() and .model_dump_json()
• [ ] JSON Schema
• [ ] Dataclasses
• [ ] Model Config
• [X] Field Types - adding or changing a particular data type
• [ ] Function validation decorator
• [ ] Generic Models
• [ ] Other Model behaviour - model_construct(), pickling, private attributes, ORM mode
• [ ] Plugins and integration with other tools - mypy, FastAPI, python-devtools, Hypothesis, VS Code, PyCharm, etc.

[sydney-runkle]

This could belong in pydantic-extra-types! Moving this there now!