Updates MFEMReader and winding number example

[kennyweiss]

Summary

This PR adds a few improvements centered around improvements to the quest winding number example

• Improves and cleans up MFEMReader
  • Can now read in multispan NURBS meshes (no longer hardcodes knot vector for a single span)
  • Fixed a bug in mapping attributes to curves. We no longer assume the attributes start at 1 and are contiguous.
    Instead, we add an optional array to map the returned curves to their attributes.
• Improves quest winding number example
  • Adds flag to enable/disable memoization (on by default)
  • Adds optional caliper support
  • Updates to svg2contours script which convets an SVG to an mfem Mesh file
    • When finding the SVG resolution, prefer viewBox info, followed by height and width
    • Updates dependency to svgpathtools@1.7.2, which incorporates our patch (and removes the patch
    • Also updates environment setup to use uv instead of venv
• Improves error reporting in Klee/Shaping
  • We also check the return code when reading a file
  • We now throw an error when the requested file does not exist (or cannot be opened)
  • This was a user request since missing files in the shaping app are not a recoverable error, and the warning message was obscured by later resulting failures
• Slic: Adds slic::getAbortFunction() to return the function pointer associated with the slic error handler
  • Also adds an RAII utility class slic::ScopedAbortToThrow which allow temporarily setting the abort function to throw an exception. This is helpful for testing that SLIC_ERROR/SLIC_ASSERT calls happen without gtest Death tests (which cannot run in MPI-based tests).
• Misc:
  • MPIWrapper now only finalizes MPI if it initialized it
  • Fixes a few tests so they can run through MPI
  • Fixes some warnings about unused variables

[Arlie-Capps]

Thanks, Kenny!

[jcs15c]

Looks good to me, thanks for the updates!