Clarifies that requesting no conversion is part of the codec factory, and
future refactors will make the codec factory less opionated about conversion.
Kubernetes-commit: 7f9dfe58f4cbe1e1b9e80f52addff70bac87bed4
Scheme conversion should support unstructured conversion natively to
allow going from unstructured to typed and back. It is not a higher
level responsibility to do that conversion because the scheme is the
only one who knows what types it supports.
Kubernetes-commit: 557f9ddfe6300ecdbdd70ea67dca63bf6b710ea7