Incorporate aas-test-engines for server testing with `Neo4jObjectStore` backend

[zrgt]

We should integrate aas-test-engines for testing.

To do this we run a Basyx-Python-SDK server with our Neo4jObjectStore and run aas-test-engines to test it. By doing it we automatically test:

• Neo4jObjectStore
• AAS-to-Neo4j Import (Implemented in Neo4jObjectStore)
• AAS-from-Neo4J Extraction (Implemented in Neo4jObjectStore)

@thammel We can take a look at the following PR (eclipse-basyx/basyx-python-sdk#429) in basyx-python-sdk and do it in a similiar way.

[thammel]

I have implemented the core logic in my fork

[thammel]

I have now refactored the test-engines into the test directory.
I dont know why but two different runs have different outcomes.
The first was run on a different branch and the outcome is equal to that from the last action on basyx-python.
The second is the last identicily version on my inital branch that fails once again the metadata test