Place fortran modules in unique directory, copy dir on install into c…

[dholladay00]

…orrect install dir. No longer need to know module names a priori.

PR Summary

This PR makes the installation of fortran modules more robust in that module naming conventions need not be known. This is an issues on cray machines under certain conditions. This will serve as a template for how to handle this in related projects.

@rbberger @mauneyc-LANL

PR Checklist

• Adds a test for any bugs fixed. Adds tests for new features.
• Format your changes by using the make format command after configuring with cmake.
• Document any new features, update documentation for changes made.
• Make sure the copyright notice on any files you modified is up to date.
• After creating a pull request, note it in the CHANGELOG.md file
• If preparing for a new release, update the version in cmake.

[mauneyc-LANL]

I don't have an issue with this approach, but I do want to point how I've dealt with this in the past.

$> man crayftn
## ... ##
• The -ef option is a modifier to the -em option.  If -ef is specified, the output goes to modulename.mod rather than MODULENAME.mod

so something like

if(${CMAKE_Fortran_COMPILER_ID} STREQUAL "Cray")
  target_compile_options(singularity-eos PRIVATE "$<$<COMPILE_LANGUAGE:Fortran>:-ef>>")
endif()

(the PRIVATE only passes the option to singularity-eos so it doesn't get passed downstream)

AFAIK, crayftn is the only compiler to do this by default.

[mauneyc-LANL]

FWIW, this is an ongoing issue with CMake https://gitlab.kitware.com/cmake/cmake/-/issues/19608