feat(NewDeviceVerification) :
Added constat for the cache key in Bit.Core because the cache key format needs to be shared between the Identity Server and the MVC Admin project.
Updated DeviceValidator class to handle checking cache for user information to allow pass through.
Updated and Added tests to handle new flow.
* feat(BaseRequestValidator):
Add global setting for new device verification.
Refactor BaseRequestValidator enabling better self-documenting code and better single responsibility principle for validators.
Updated DeviceValidator to handle new device verification, behind a feature flag.
Moved IDeviceValidator interface to separate file.
Updated CustomRequestValidator to act as the conduit by which *Validators communicate authentication context between themselves and the RequestValidators.
Adding new test for DeviceValidator class.
Updated tests for BaseRequestValidator as some functionality was moved to the DeviceValidator class.
refactor(TwoFactorAuthentication): Remove references to old Duo SDK version 2 code and replace them with the Duo SDK version 4 supported library DuoUniversal code.
Increased unit test coverage in the Two Factor Authentication code space. We opted to use DI instead of Inheritance for the Duo and OrganizaitonDuo two factor tokens to increase testability, since creating a testing mock of the Duo.Client was non-trivial.
Reviewed-by: @JaredSnider-Bitwarden
