Encoding for JWT during import

[albertolerda]

Currently, a JWT is represented as a dictionary

{
    header: { ... },
    payload: { ... },
    signature:  ... 
}

To sign a JSON we have to encode it, which is generally not deterministic (for an import from the outside).
Inside zencode it is fine keeping it as a dictionary (because the encoding is deterministic), the problem is with the sd jwt.

From the outside, the user can decide whether to use sd jwt (which is encoded) or signed selective disclosure

For the inside the jwt is an or, either the previous or

{
    header: "base64",
    payload: "base64,
    signature: ...
}

[jaromil]

Point of intervention: