[Magic] Implement elemental affinities and clean up elemental staves old mess

[Xaver-DaRed]

I affirm:

• I understand that if I do not agree to the following points by completing the checkboxes my PR will be ignored.
• I understand I should leave resolving conversations to the LandSandBoat team so that reviewers won't miss what was said.
• I have read and understood the Contributing Guide and the Code of Conduct.
• I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

• Implements new multiplier step for magic damage, which uses some modifiers which were unused until now. (Elemental MAB/elemental affinity)
• Renames said modifiers from ELEMENTATT to ELEMENT_MAB for clarity.
• Unifies elemental staves "affinity" modifiers for DMG and MACC into 1 set.
• Renames said modifiers to better match what they actually are, (aka NOT affinity)
• Cleanup several modifiers in gear. Some pieces of gear are unrelated to this changes, but I saw them and were SO wrong that they couldnt be kept there.

And all of this while lowering the overall number of lines.

Documentation:
https://www.bg-wiki.com/ffxi/Magic_Damage#Affinity
https://www.bg-wiki.com/ffxi/Category:Elemental_Staves

Steps to test these changes

Use magic with and without staves and have everything work equal to or better than before