Fix base modifiers showing up as explicit mods

[Wires77]

Fixes #1254

Description of the problem being solved:

Copying items from in-game separates out each damage type instead of grouping them as "Elemental Damage" like in PoE1. This PR also ignores the "Requires" line, as it comes from the base item.

The bow in the linked issue has already been mangled by our reformat, so it would have to be re-imported from the game to see the fix there.
Tested with this item:

Item Class: Two Hand Maces
Rarity: Rare
Skull Crack
Crumbling Maul
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Physical Damage: 90-114 (augmented)
Fire Damage: 6-10 (fire)
Critical Hit Chance: 6.01% (augmented)
Attacks per Second: 1.16 (augmented)
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Requires: Level 38, 68 (unmet) Str
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Item Level: 38
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Gain 1 Rage on Hit (enchant)
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Causes Enemies to Explode on Critical kill, for 10% of their Life as Physical Damage (implicit)
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33% increased Physical Damage
Adds 6 to 11 Physical Damage
Adds 6 to 10 Fire Damage
+50 to Accuracy Rating
+1.01% to Critical Hit Chance
5% increased Attack Speed
+6 to Strength
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Corrupted