define MKDTrait fields

[GurgumXIV]

This is my first time working with this repo, and there were a couple of issues I didn't know how to resolve:

• Row 0 in MKDSupportJob is Phantom Freelancer, so that name is showing up in the MKDSupportJob column of MKDTrait for rows that have no other data.
• The Icon ID is -1 instead of 0 for the empty rows, so an error is displayed ("Failed to convert integer value") instead of Icon 0 (blank icon).

[github-actions]

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