CIP-0129/CIP-0105 Backward compability

[paweljakubas]

Why?

We have already supported CIP-0129, but in order to avoid nasty surprises it would be good to support in full deprecated CIP-0105

What?

At this moment we support credentials
drep : payload is specific byte + 28-byte key hash
drep : payload is specific byte+ 28-byte script hash

We are going to support additionally
drep: payload is 28-byte key hash (deprecated)
drep_script: payload is 28-byte script hash
drep_vkh : payload is 28-byte key hash

How?

We are going to improve swagger + text-to-drep functionality plus extend quickcheck generators and include proper positive and to-fail cases in malformed