Add `zod` for validation of specific mdoc credentials like mDL

[berendsliedrecht]

mDL is a well defined cbor structure and we can validate it when the library receives the input (and make it typed based on whether we know the namespace).

we should create zod schemas based on the mDL specification (and possibly also the eu PID, depends how far we want to go) and validate the user input. If we do this we make sure that the mdoc created is always spec compliant if we are aware of the spec and the structure, it would also still allow to create arbitrary mdocs if we do not have a schema for it.

[TimoGlastra]

I think we could probably also do it for other input where manual validation is done now