Obey StateStruct::output in writing the Exodus file.

Quoting an explanatory doc in Albany_GenericSTKFieldContainer_Def.hpp:

//amb 13 Nov 2014. After new STK was integrated, fields with output set to false
// were nonetheless being written to Exodus output files. As a possibly
// temporary but also possibly permanent fix, set the role of such fields to
// INFORMATION rather than TRANSIENT. The enum RoleType is defined in
// seacas/libraries/ioss/src/Ioss_Field.h. Grepping around there suggests that
// fields having the role INFORMATION are not written to file: first,
// INFORMATION is never actually used; second, I/O behavior is based on chained
// 'else if's with no trailing 'else'; hence, any role type not explicitly
// handled is not acted on.
//   It appears that the output boolean is used only in this file in the context
// of role type, so for now I'm applying this fix only to this file.