Deal with RawBytes ambiguity

[Stebalien]

RawBytes was intended for "cbor-serialized" data but we use it for other byte vectors because it's convenient. We should either:

1. Update the documentation to reflect that RawBytes has no opinions on the serialization of the data.
2. Introduce a better type for "byte vec". We already have one BytesDe, but the name isn't great and we don't use it frequently.

[anorth]

Thanks. Pending arguments about why it should be opinionated about format (preferably backed up by enforcement) I prefer option (1). I have forgotten it once was opinionated since at least the time we switched to Rust.

[Stebalien]

Yeah, that seems reasonable.

[Stebalien]

Although... maybe introduce a RawCbor type?