prepare signed SDs for FC presentation and handover

Colleagues, we need sample SDs which we can use for presentations etc, which validates against latest schemas.. right now we have 1 sample Participant SD and 1 sample Offering SD which validates against schemas, but they have no proofs: https://gitlab.com/gaia-x/data-infrastructure-federation-services/cat/fc-service/-[…]c/test/resources/VerificationService/syntax/legalPerson2.jsonld, https://gitlab.com/gaia-x/data-infrastructure-federation-services/cat/fc-service/-[…]st/resources/VerificationService/syntax/serviceOffering2.jsonld