[Bug] Python Wrapper LinkSecret Invalid object handle

[PatStLouis]

When attempting to transform a LinkSecret to json I get the following error:
anoncreds.error.AnoncredsError: Invalid object handle

Steps to reproduce:

link_secret = LinkSecret()
print(link_secret.to_dict())

[TimoGlastra]

Link secret is now a string. It should probably be updated in the python wrapper as well. @blu3beri do you know what needs to be chaned?

[PatStLouis]

Ok good to know. Ideally there should be a way to serialize the object and load it back. The LinkSecret.load() method expects a json as input and throws undefined symbol: anoncreds_link_secret_from_json. This makes it difficult to store/restore the link secret in-between data-flows such as creating a credential request and/or deriving a presentation.

[TimoGlastra]

There's no need anymore to serialize/dezerialize it. If you look at the JS wrapper it has a single LinkSecret.create which returns a string. All other methods now expect a string when you need to pass the link secret