Draft: Remove MEDLoader dependency in stbtel_converter

Reference issue

None

Description

When converting a mesh to MED format using converter.py, MEDLoader is required in order to add boundary information to the resulting MED mesh. This MR removes this requirement by extracting boundary edges in converter.f and converting boundary types from node-based to edge-based.

In addition, a very fast integer array sort function using the merge sort algorithm has been added.

Checklist

All Merge Requests:

• Update NEWS.txt to describe your changes.
• Run compile_telemac.py --check to check FORTRAN coding conventions.
• Run pylint to check Python coding conventions.
• If you added new files, run compile_telemac.py --clean --rescan and commit the updated cmdf file(s) accordingly.
• Run compile_telemac.py --clean for both normal and debug configurations.
• Run validate_telemac.py for both normal and debug configurations.
• Run validate_telemac.py --notebook for both normal and debug configurations.
• Run doc_telemac.py if there are any modifications in the documentation.
• Run damocles.py --eficas if there are any modifications in the dictionaries.

In addition, for a new feature:

• Check that your feature works in both serial and parallel modes.
• Add at least one test case to check the functionality (with documentation, graphics and VnV script)
• Update the documentation for the module in which your feature will be available.