Add TCGPlayer set names for each set

[Sembiance]

This would allow people who use MTGJSON to more easily integrate into TCGPlayer prices.

[pawelkata]

If it wouldn't be too big of a problem, I'd appreciate set names according to MKM (which is like TCGPlayer but for Europe). Here's the link to their category naming table: https://www.magiccardmarket.eu/Expansions . If I can be of help on this matter, I'm available.

[Sembiance]

@pawelkata I've opened a different issue to track adding those set names, see Issue #67

[Sembiance]

A user created the attached JSON file that has mappings to the TCGPlayer names. I've attached it here.

MTGJson_Sets_with_TCGPlayer.json.txt