Issue 1595 - Implement Modulus and scale_factor computation

[lsawade]

Description

• Implements compute factor / properties used for modifying scaling kappa and mu and computing factors used in the solution of the memory step.

Issue Number

Closes #1595

Checklist

Please make sure to check developer documentation on specfem docs.

• I ran the code through pre-commit to check style
• THE DOCUMENTATION BUILDS WITHOUT WARNINGS/ERRORS
• I have added labels to the PR (see right hand side of the PR page)
• My code passes all the integration tests
• I have added sufficient unittests to test my changes
• I have added/updated documentation for the changes I am proposing
• I have updated CMakeLists to ensure my code builds
• My code builds across all platforms