Fix issues around scaleability and Runegraft of the Bound

Revisiting this code when looking over this PR makes me realize there are a few more hidden gotchas here.

1. Making a mod unscalable in a LIST mod doesn't do anything. An example of this would be "banners also cause enemies to take (%d+)%% increased damage". This code only checks for unscalable at the LIST level, not for each subMod: https://github.com/PathOfBuildingCommunity/PathOfBuilding/blob/78326a60910b00739c5f33be69cb140cd164a12c/src/Classes/ModStore.lua#L37-L50
2. Unscaleable mods get added twice. I tested "take no extra damage from critical strikes" and saw the value double (even though there is a hard cap on a lot of these unscalable mods

In short, I'll merge this PR but I needed to write this down somewhere so it can be refactored again, with proper test cases added for all these corner cases.

Originally posted by @Wires77 in https://github.com/PathOfBuildingCommunity/PathOfBuilding/issues/8977#issuecomment-3251710545

Start in src/Classes/ModStore.lua at the linked scaleability logic and trace how LIST mods and unscalable mods are processed. Add test cases for per-subMod unscalable handling and duplicate application, then verify that the affected modifiers produce the expected values without double counting.