refactor(primitvies): remove roundtrip-safe structs from primitives

[scarmuega]

No description provided.

[sterraf]

It seems necessary to implement the corresponding serde traits for KeepRaw, in order to have the same functionality. Should they be "transparent", i.e., ignoring the CBOR data? Or the derived ones for KeepRaw work well?

Today, derived traits are not the same for Minted vs plain structs:

#[derive(Serialize, Deserialize, Encode, Decode, Debug)]
pub struct Tx {
    ...

vs

#[derive(Encode, Decode, Debug, Clone)]
pub struct MintedTx<'b> {
    ...

[scarmuega]

@sterraf KeepRaw should be transparent for serde.

[sterraf]

There are instances of roundtrip-safe structs that have to be moved inside of a KeepRaw, namely:

pub struct MintedBlock<'b> {
    #[n(0)]
    pub header: KeepRaw<'b, MintedHeader<'b>>,

    #[b(1)]
    pub transaction_bodies: MaybeIndefArray<KeepRaw<'b, TransactionBody>>,

In order to safely switch to Vec, it would be natural to do:

    pub transaction_bodies: KeepRaw<'b, Vec<TransactionBody>>,

This motivates: Should Minted structs (which are going to be default by #604) have a more uniform layout, as in "each field is a KeepRaw?