Asset files for primary trade goods

[edurne85]

This epic covers these categories of goods:

• Mining (Ores, metal bars, stone)
• Clothes and Leather
• Herbs
• Enchanting reagents
• Pigments
• Gems (simple and socketed)

Tiers to implement:

• [x] #529
• [x] #530
• [x] #532
• [x] #533
• [ ] Master (BC) tier
• [ ] Grand Master (WotLK) tier
• [ ] Illustrious Grand Master (Cata) tier
• [ ] Zen (MoP) tier
• [ ] Draenic (WoD) tier
• [ ] Demonic (Legion) tier
• [ ] BfA tier
• [ ] Shadowlands tier
• [ ] Dragonflight tier

[edurne85]

Note: secondary goods (Meat, Fish, Elemental, common / vendor, and possibly others) will be handled on a separate epic (#539 ).

[edurne85]

Marked as paused: first four tiers completed, further ones are not a priority.