[WIP] Implement HYPRE solver on top of diffusion example

[acreyes]

PR Summary

This probably shouldn't merge. Adds an AMG preconditioned solver in hypre alongside the existing parthenon solver for performance comparison only. This mirrors the way that FLASH interfaces with HYPRE and paramesh through the SStruct interface.

PR Checklist

• Code passes cpplint
• New features are documented.
• Adds a test for any bugs fixed. Adds tests for new features.
• Code is formatted
• Changes are summarized in CHANGELOG.md
• Change is breaking (API, behavior, ...)
  • Change is additionally added to CHANGELOG.md in the breaking section
  • PR is marked as breaking
  • Short summary API changes at the top of the PR (plus optionally with an automated update/fix script)
• CI has been triggered on Darwin for performance regression tests.
• Docs build
• Any contribution that was created or modified with the assistance of generative AI must have a comment disclosing this such as // This file was made in part with generative AI.
• (@lanl.gov employees) Update copyright on changed files