[FEATURE] Implement AAS 3.1 in Discovery Service

[arnoweiss]

Is your feature request related to a problem?
The 3.1 spec has been out for more than 6 months now. As Catena-X has updated standard CX-0002 to demand compliance with AAS 3.1, Basyx should reflect that. For the DTR component, especially new new endpoint on the Discovery serivce is critical.

Describe the solution you'd like
Implement the POST /lookup/shellsByAssetLink endpoint

Describe alternatives you've considered
stay on 3.0. Not an option as dependant standards have already upgraded. GET /lookup/shells was always underspecified.

[aaronzi]

Good point. We will have a look at this after Christmas