`model.datatypes`: `UnsignedInt` mapped to wrong XSD name, `UnsignedByte` missing from `XSD_TYPE_NAMES`

[s-heppner]

Currently, XSD_TYPE_NAMES in basyx/aas/model/datatypes.py contains a typo and a missing entry:

• UnsignedInt is mapped to "unsignedByte" instead of "unsignedInt"
• UnsignedByte has no entry at all

Because XSD_TYPE_CLASSES is generated as the inverse of XSD_TYPE_NAMES, this produces three concrete failures:

• XSD_TYPE_CLASSES["xs:unsignedInt"] is absent → deserializing any Extension, Property, Qualifier, etc. with valueType: xs:unsignedInt raises a KeyError
• XSD_TYPE_CLASSES["xs:unsignedByte"] returns UnsignedInt instead of UnsignedByte → silent wrong-class deserialization
• XSD_TYPE_NAMES[UnsignedByte] raises a KeyError → serialization of UnsignedByte values is also broken

Both the JSON adapter (json_deserialization.py) and XML adapter (xml_deserialization.py) look up valueType strings through XSD_TYPE_CLASSES, so both serialization formats are affected.

The AAS spec (IDTA-01001), aas.json, and AAS.xsd all define xs:unsignedInt (32-bit, 0–4 294 967 295) and xs:unsignedByte (8-bit, 0–255) as distinct, valid data types.

Fix: in basyx/aas/model/datatypes.py, replace:

UnsignedInt: "unsignedByte",