Move 0x9c packet intercept so we can use UnitAny

[fergushev]

Previous mechanism to completely hide items:

• Intercept 0x9c packet before it gets sent to the D2Client functions that handle item creation
• Build ItemInfo from the packet bitstream (all packet actions)
• Run loot filter rules using ItemInfo (if packet action == 0 or 3)
• If a match was found and the name was empty, then block the packet (i.e. don't pass it along to the client)

New mechanism:

• Intercept 0x9c packet at the point where the item gets created (only for packet action 0 and 3)
• Send the packet along to the client so the unit gets created
• Get unit and build UnitItemInfo
• Run loot filter rules using UnitItemInfo
• If a match is found and the name is empty, add the nodraw flag to the item (UNITFLAGEX_INVISIBLE)

There's a lot of code that can be removed now too, but I'll save that for a separate PR (ParseItem & ProcessStat in ItemMover, all of the EvaluateInternalFromPacket functions in ItemDisplay, etc.)

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(public patch notes) New Features and improvements:

• Hidden gold will now automatically be picked up

Bug Fixes:

• Fixed a bug with PRICE that would cause the condition to incorrectly return false in certain cases