adapter.aasx: Allow reading AASX with wrong relationship (#381)

There are many AASX in the wild where there is an
additional `www` in the relationship definition 
that does not belong there:
```
http://www.admin-shell.io/aasx/relationships/aasx-origin
```
whereas it should be according to the 
[specification]:
```
http://admin-shell.io/aasx/relationships/aasx-origin
```

Previously, our SDK did not allow for reading 
these AASX files with wrong relationship URL. 
However, since there are so many of them, 
this change enables them to be read, while 
notifying the user with a big warning message 
that their AASX file is actually not standard 
compliant and needs to be changed 
(see discussion in #381).

Fixes #379 
Fixes #383 

[specification]: (https://industrialdigitaltwin.org/wp-content/uploads/2024/06/IDTA-01005-3-0-1_SpecificationAssetAdministrationShell_Part5_AASXPackageFileFormat.pdf#Page=18)

Author: jsejdija

sdk/basyx/aas/adapter/aasx.py

@@ -143,7 +143,20 @@ def read_into(self, object_store: model.AbstractObjectStore,
         try:
             aasx_origin_part = core_rels[RELATIONSHIP_TYPE_AASX_ORIGIN][0]
         except IndexError as e:
-            raise ValueError("Not a valid AASX file: aasx-origin Relationship is missing.") from e
+            if core_rels.get("http://www.admin-shell.io/aasx/relationships/aasx-origin"):
+                # Since there are many AASX files with this (wrong) relationship URls in the wild, we make an exception
+                # and try to read it anyway. However, we notify the user that this may lead to data loss, since it is
+                # highly likely that the other relationship URLs are also wrong in that file.
+                # See also [#383](https://github.com/eclipse-basyx/basyx-python-sdk/issues/383) for the discussion.
+                logger.warning("SPECIFICATION VIOLATED: The Relationship-URL in your AASX file "
+                               "('http://www.admin-shell.io/aasx/relationships/aasx-origin') "
+                               "is not valid, it should be 'http://admin-shell.io/aasx/relationships/aasx-origin'. "
+                               "We try to read the AASX file anyway, but this cannot guaranteed in the future,"
+                               "and the file may not be fully readable, so data losses may occur."
+                               "Please fix this and/or notify the source of the AASX.")
+                aasx_origin_part = core_rels["http://www.admin-shell.io/aasx/relationships/aasx-origin"][0]
+            else:
+                raise ValueError("Not a valid AASX file: aasx-origin Relationship is missing.") from e
 
         read_identifiables: Set[model.Identifier] = set()