support refresh token scopes

[nrwiersma]

While oAuth2 does not require scope on a refresh, OIDC can support this (seems to be a mixed bag on this). As this library is largely used for OIDC it would be good to support this use case.

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[vijaytdh]

👍 It would be great if this is reviewed and eventually merged as there are a number of similar PRs from people affected by this issue with the refresh token and scopes.