Default attributes were only handled by ODS accessors generated with the
intention that these behave as if set attributes. This addresses the
long standing TODO to address this inconsistency. Moving the
initialization to construction vs every access. Removing need for
duplicated default attribute population in python bindings.
Switch OpenMP ones to optional attribute with default as the currently
set default values are not legal.
Switched LinAlg generated ones to optional attribute with default as its
quite widely used and unclear where it falls on two different