[Refactor] Standardize "damage taken" modifier usage

[Xaver-DaRed]

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What does this pull request do?

This is current usage:

• Physical SDT modifiers: Defined as a float in database, fetched as an uint, stored in a base 1000 modifier where base 100% damage = value of 1000
• Elemental SDT modifiers: Defined as an int in database, fetched as an int, stored in a base 10000 modifier where base 100% damage = value of 0 (sane) BUT 50% less damage = 5000 and 50% more damage = -5000
• Other SDT modifiers: Defined as an int in database, fetched as an int, stored in a base 10000 modifier where base 100% damage = value of 0, 50% less damage = -5000 and 50% more damage = 5000

This is new usage:

• All SDT modifiers are defined as an int in database, fetched as an int, stored in a base 10000 modifier where base 100% damage = value of 0, 50% less damage = -5000 and 50% more damage = 5000

Steps to test these changes

Fight mobs. Cast spells.

[UmeboshiXI]

Just thought of some not functional but for documentation. The mod enum has comments relating to the old physical SDTs not being the same base values as the others.

[zach2good]

I don't know if this ever came up in the past, but should we rename these mods to imply that they're 1/10000 1e4-based, etc.

SLASH_SDT -> SLASH_SDT_BASE_10K? Just really hammer it home forever? I wouldn't be against us marking other things with types too: ..._FLOAT, _PERCENT, _something that indicates 0.0 to 1.0, etc.

[Xaver-DaRed]

I wouldnt be opposed to changing the modifier naming conventions. Or implementing a convention in the first place.

With this change, now all _SDT mods use 10k as base and all function the same (positive -> more damage, negative .> less damage)
This was more something that was bound to happen. We started this a year or 2 ago and we just didnt finish it.