WIP stuff for wiki item template

[acbeaumo]

Abstract

A couple of changes related to item exports for the wiki.

Action Taken

Added skill_icon and drop_rarities_ids to the list of parameters that PyPoE won't overwrite.

• skill_icon is future stuff for transfigured skill gems that hasn't been implemented into the wiki yet
• drop_rarities_ids is stored in a Cargo table, but it's not used for anything currently. This field is meant to hold the rarities that an item can be obtained at. This could be used in wiki templating, but in some cases editors need to be able to specify drop_rarities_ids without PyPoE overwriting.
• is_relic is not used

Replaced the bogus parameter base_metadata_id with the correct parameter base_item_id.

• Transfigured skill gems are derived from the base skill gem. base_item_id holds the metadata id of the base skill gem.