credential_identifiers should remain consistent after use of refresh token

The behaviour when refresh tokens are used doesn't seem to be entirely clear and I think we could clarify.

https://datatracker.ietf.org/doc/html/rfc9396#section-7 says:

In addition to the token response parameters as defined in [RFC6749], the AS MUST also return the authorization_details as granted by the resource owner and assigned to the respective access token.

So I think authorization_details needs to be returned in the refresh token response if it was returned in the original request.

I would suggest it would be sensible that credential_identifiers MUST be consistent - i.e. if the wallet still has access to the same set of credential datasets, the exact same credential_identifiers must be returned (i.e. the issuer must not assign new identifier values that represent the same credential datasets). But values could be added or removed if the wallet now has access to fewer or more Credential Datasets.

Start by reading RFC 9396 section 7 and the repository's refresh-token response requirements, though no repository file or test is named in the issue. Clarify when authorization_details and credential_identifiers must be returned and preserved, then confirm the specification states the resulting behavior unambiguously.