Fix mirrored items in character imports

[AdamZ-8113]

Fixes # N/A

Description of the problem being solved:

Mirrored items were not displaying the "Mirrored" tag when imported via the character import workflow. This is because GGG's item API uses the duplicated field on mirrored items, but the character import workflow was only checking itemData.mirrored.

This maps itemData.duplicated to PoB's existing mirrored state while retaining itemData.mirrored as a compatibility fallback.

The existing 3.29 item API import test now supplies duplicated = true and verifies that the resulting item is mirrored.

Steps taken to verify a working solution:

• Import a character with a mirrored item.
• In this case I was looking at Halnao#2882 , character HaL_Allflame . They have a rare ring named Death Nail that has the mirrored tag. Viewable on PoE.Ninja here https://poe.ninja/poe1/builds/allflame/character/Halnao-2882/HaL_Allflame

Link to a build that showcases this PR:

See above

Before screenshot:

After screenshot: