[Magiclysm] Tune channeling spells with scale modifier

[MNG-cataclysm]

Summary

Mods "Tune channeling spells with scale modifier."

Purpose of change

Continue improving and tweaking spellcasting proficiencies, this time with channeling.

Describe the solution

Much like #72740, add a scale modifier to channeling spells, and add values that will tune channeling benefits to make them more worthwhile and powerful.

Describe alternatives you've considered

Not doing this.

Testing

Everything works fine, no apparent errors on game start or while playing.

Additional context

This is based off of #72740, and it is part of the same project.