* feat: add VerificationAttempt model to verify_student application
This commits adds a VerificationAttempt model to store implementation and provider agnostic information about identity verification attempts in the platform.
* feat: add api for VerificationAttempt model
* fix: error handling for update
- added tests accordingly
- also took care of some nits
* chore: lint
* chore: lint for equals spaces
* feat: using generic update function instead
- can now update name, status, and exp. date on generic attempts
- changed tests accordingly
- a few nits
* chore: fix docstring args
* fix: corrected status validation
- reverted to old status validation method
- fixed tests accordingly
* fix: datetime, status, and annotation fixes
- expiration_datetime can be updated to None
- VerificationAttemptStatus is now StrEnum
- Added type annotations for api functions
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Co-authored-by: michaelroytman <mroytman@edx.org>
