Improve usability of the XFSC Catalogue with regards to the Gaia-X Lab Wizard

As discussed in the XFSC Catalogue Developers' Community Call on the 27th of October, one reoccurring constraint when working with the XFSC catalogue is that it does not accept credentials created using the Gaia-X Lab Wizard. In order to enable using the XFSC catalogue alongside the Gaia-X Lab Wizard, we identified three points that require changes in the current implementation of the XFSC Catalogue.

• Add the schema used by the Gaia-X Lab as default schema to the XFSC Catalogue
• Ensure that the catalogue accepts Credentials of the type used by the Gaia-X Lab Wizard. This can be achieved in two ways:
  1. Change the implementation of the catalogue to accept the different namespaces
  2. Expand the schema used by the Gaia-X Lab with subclass relations to the core classes accepted by the XFSC Catalogue
• Support the signatures used by the Gaia-X Lab (see #178 (closed))