EXT-8636 FIXED updating wearables (worn) prefix in 'My Outfits' list.

- Fixed LLOutfitsList COF changes handler to update worn status of items removed from COF. Now they are updated based on the differences in original items' ids in COF.
- Fixed 'My Outfits' items worn status check to update depending on whether the item is linked in COF or not.
This is a kind of workaround to fix updating attachments' worn status because LLAppearanceMgr::updateAppearanceFromCOF is triggered erlier than new attachment links are fetched. When dumpItemArray(obj_items,"asset_dump: obj_item") is called from LLAppearanceMgr::updateAppearanceFromCOF, all attachment links have empty asset ids.

Reviewed by Vadim Savchuk at https://codereview.productengine.com/secondlife/r/859/.

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branch : product-engine