[KeyManager] Reduce KeyRegistry complexity #667
Description
We have KeySpec, KeyMetadata, and KeyRecord. We could probably do away with one of those, to cut down on cognitive overhead. We can consider merging all fields of KeyMetadata into KeyRecord - and perhaps s/KeySpec/KeyMetadata/, since a "key spec" to seems to imply algorithms and policies but not data about specific keys, and the current fields in KeySpec seem metadata-ish.
From @bluegate010 comment at #649 (comment)