[lldb/python] Use PythonObject in LLDBSwigPython functions

Return our PythonObject wrappers instead of raw PyObjects (obfuscated as
void *). This ensures that ownership (reference counts) of python
objects is automatically tracked.

Differential Revision: https://reviews.llvm.org/D117462

lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp

@@ -280,7 +280,8 @@ StructuredData::ObjectSP PythonObject::CreateStructuredObject() const {
   case PyObjectType::None:
     return StructuredData::ObjectSP();
   default:
-    return StructuredData::ObjectSP(new StructuredPythonObject(m_py_obj));
+    return StructuredData::ObjectSP(new StructuredPythonObject(
+        PythonObject(PyRefType::Borrowed, m_py_obj)));
   }
 }