Hash token guard credentials during validation

[Nipun404]

This pull request updates TokenGuard::validate to respect hashed token storage.

TokenGuard::user already hashes the incoming token before retrieving the user when the guard is configured with hashed token storage. However, TokenGuard::validate was passing the raw token to the user provider, which caused validation to fail for valid plain-text tokens when the stored API token is hashed.

This change makes validate use the same hashing behavior as user.

A regression test has been added to verify that hashed token validation passes the hashed credential value to the user provider.

[taylorotwell]

I am closing this pull request because it lacks sufficient explanation, tests, or both. It is difficult for us to merge pull requests without these things because the change may introduce breaking changes to the framework.

Feel free to re-submit your change with a thorough explanation of the feature and tests - integration tests are preferred over unit tests. Please include it's benefit to end users; the reasons it does not break any existing features; how it makes building web applications easier, etc.

Thanks!