feat: add ability to allow token refresh from hook without overriding the session claims

[zachabney]

Documentation corresponding to PR ory/hydra#3146

The refresh token hook currently requires a 200 response code with an updated session payload. There is no way to permit the token refresh without overriding the session data. It's useful, however, to be able to use the token refresh hook in order to accept/reject token refreshes without the need to update the session data.

This adds the ability for the token refresh hook to return a 204 No Content response code to indicate that the token refresh is permitted, but not to update the session data.

Related Issue or Design Document

ory/hydra#3082

Checklist

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• I have referenced an issue containing the design document if my change introduces a new feature.
• I have read the security policy.
• I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security
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• I have added tests that prove my fix is effective or that my feature works.
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[achedeuzot]

Hey, strangely enough, merging this commit removed the changes brought in PR #1019
I'm not sure that was expected.