Add HDF5 + XDMF output module

[SpeedyTurtle599]

Description

This PR adds native HDF5+XDMF output support to MFC's post-processor as a portable alternative to Silo-HDF5 format. The new format (format=3) produces standard HDF5 data files with XDMF metadata that works reliably with ParaView 5.12+ and other XDMF-compatible visualization tools without requiring Silo library installation.

Key Features

• Native HDF5+XDMF output module (m_hdf5_xdmf_output.fpp): Complete implementation supporting 1D/2D/3D structured grids, particle/bubble data, and all flow variables
• Single/double precision support: Variable data respects the precision parameter (1=32-bit, 2=64-bit); grid coordinates always use double precision for accuracy
• Time series XDMF: Master time_series.xdmf file references all timesteps for animated visualization in ParaView
• HDF5 metadata attributes: Stores spatial_extent (bounding box) and data_range (min/max) for future visualization optimization
• Test framework updates: Proper validation of HDF5+XDMF output files with directory traversal fix
• 6 regression tests: Based on existing 1D/2D/3D examples covering shock tubes, vortex, and bubble collapse

Type of change

• New feature (non-breaking change which adds functionality)

Scope

• This PR comprises a set of related changes with a common goal

How Has This Been Tested?

• Built and ran all 6 new HDF5+XDMF test cases (BAC4B871, 682BAB49, 9A210C81, 303ECD53, 2087DEB9, B30CF683)
• Verified XDMF files load correctly in ParaView 5.12+
• Validated HDF5 file structure with h5dump
• Ran existing test suite to ensure no regressions

Test Configuration:

• macOS with GNU Fortran 15.2.0, HDF5 with Fortran bindings
• CPU-only build (this feature is post-process only, no GPU code)

Checklist

• I have added comments for the new code
• I added Doxygen docstrings to the new code
• I have made corresponding changes to the documentation (docs)
• I have added regression tests to the test suite so that people can verify in the future that the feature is behaving as expected
• I have added example cases in examples that demonstrate my new feature performing as expected. (Tests use existing examples with format=3)
• I ran .mfc.sh format before committing my code
• New and existing tests pass locally with my changes, including with GPU capability enabled (both NVIDIA hardware with NVHPC compilers and AMD hardware with CRAY compilers) and disabled
• This PR does not introduce any repeated code (it follows the DRY principle)
• I cannot think of a way to condense this code and reduce any introduced additional line count

If your code changes any code source files (anything in simulation)

N/A - This PR only modifies post_process which runs on CPU only.

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[sbryngelson]

Please add documentation. Aside from the usual documentation we do, it would be useful to have a "guide" on how and when to use different I/O options.

[codecov]

Codecov Report

❌ Patch coverage is 1.56250% with 189 lines in your changes missing coverage. Please review.
✅ Project coverage is 43.58%. Comparing base (df782b5) to head (5d7ebef).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
src/post_process/m_hdf5_xdmf_output.fpp	0.00%	171 Missing ⚠️
src/post_process/m_data_output.fpp	10.00%	16 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1101      +/-   ##
==========================================
- Coverage   43.98%   43.58%   -0.40%     
==========================================
  Files          71       72       +1     
  Lines       20284    20476     +192     
  Branches     1982     2000      +18     
==========================================
+ Hits         8922     8925       +3     
- Misses      10225    10412     +187     
- Partials     1137     1139       +2     

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