fix: handle non-top-level claims when mirroring is disabled

[elatt]

The original implementation of the mirror_top_level_claims option (#3563) simply removed the ext claim entirely when mirroring was disabled. However, we have a usecase where we want top level claims to be allowed and excluded from the ext claim but for claims that are not in the top level list, we still want them to be present in the ext claim.

Related issue(s)

#3348

Checklist

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• I have added tests that prove my fix is effective or that my feature
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Further Comments

I don't believe this should be a breaking change because the original set of tests and implementation didn't address this scenario so it looks like we should be free to add these claims back in.