Add data structures, it requires tons of refactor but it's more or less working

pkg/data/item/quality.go

@@ -0,0 +1,31 @@
+package item
+
+type Quality int
+
+const (
+	QualityNormal   Quality = 0x02
+	QualitySuperior Quality = 0x03
+	QualityMagic    Quality = 0x04
+	QualitySet      Quality = 0x05
+	QualityRare     Quality = 0x06
+	QualityUnique   Quality = 0x07
+)
+
+func (q Quality) ToString() string {
+	switch q {
+	case QualityNormal:
+		return "Normal"
+	case QualitySuperior:
+		return "Superior"
+	case QualityMagic:
+		return "Magic"
+	case QualitySet:
+		return "Set"
+	case QualityRare:
+		return "Rare"
+	case QualityUnique:
+		return "Unique"
+	}
+
+	return "UnknownItemQuality"
+}