Support loading of attribute type from MagicDraw/Cameo href to PrimitiveTypes.xmi :

umbrello/umlmodel/attribute.cpp
- In function load1 case m_SecondaryId.isEmpty() while-loop over node
  case !href.isEmpty(),
  - bool isPrimitive is set to xmiType.contains("PrimitiveType") if
    xmiType is non empty, else is set to href.contains("PrimitiveType");
  - proceed with primitive type handling if isPrimitive is true and the
    href suffix conforms to primitive type syntax.

CCBUG: 56184