Add the detailedAxialExpansion category to the fast flux parameter

[jakehader]

Description

The detailedAxialExpansion category was not applied to the fast flux block parameter and therefore mapping in the UniformMeshConverter was missing this parameter when data was being transferred. We have many parameter assignments in the framework that are not correct and there needs to be more complete audit of the parameter system, but this is just one that was reported.

---

Checklist

• This PR has only one purpose or idea.
• Tests have been added/updated to verify that the new/changed code works.

• The code style follows good practices.
• The commit message(s) follow good practices.

• The release notes (location doc/release/0.X.rst) are up-to-date with any bug fixes or new features.
• The documentation is still up-to-date in the doc folder.
• The dependencies are still up-to-date in setup.py.