[AID] Redesigning Semantic References for TD -> AID

Looking into how the semantic annotations are currently translated, we need to rethink due to the following points:

- Semantic annotations should not be converted like key-value pairs. Currently, something like `"eclass:hasQuantity": "eclass14-0:0173-1-Z4-BAJ272-003"` becomes `{"idShort": "unit", "valueType": "xs:string", "value": "eclass14-0:0173-1-05-AAA153-004", "modelType": "Property"}`. It should be done via semanticId, like how it is done for the WoT terms.
- IDTA prefers the usage of `conceptDescriptions` to store internal and even external semantic references. That means that all our semantic references need to point to a concept description in the **root** of the AAS. Implementing that requires rethinking since we cannot do that if we generate only the submodel.

I would propose starting with the first point already. The second one can be done after a thorough discussion.