feat(medusa, inventory): Inventory Management module (#2956)

* feat: inventory module

packages/inventory/src/models/inventory-item.ts

@@ -0,0 +1,44 @@
+import { Index, BeforeInsert, Column, Entity } from "typeorm"
+import { SoftDeletableEntity, generateEntityId } from "@medusajs/medusa"
+
+@Entity()
+export class InventoryItem extends SoftDeletableEntity {
+  @Index({ unique: true })
+  @Column({ type: "text", nullable: true })
+  sku: string | null
+
+  @Column({ type: "text", nullable: true })
+  origin_country: string | null
+
+  @Column({ type: "text", nullable: true })
+  hs_code: string | null
+
+  @Column({ type: "text", nullable: true })
+  mid_code: string | null
+
+  @Column({ type: "text", nullable: true })
+  material: string | null
+
+  @Column({ type: "int", nullable: true })
+  weight: number | null
+
+  @Column({ type: "int", nullable: true })
+  length: number | null
+
+  @Column({ type: "int", nullable: true })
+  height: number | null
+
+  @Column({ type: "int", nullable: true })
+  width: number | null
+
+  @Column({ default: true })
+  requires_shipping: boolean
+
+  @Column({ type: "jsonb", nullable: true })
+  metadata: Record<string, unknown> | null
+
+  @BeforeInsert()
+  private beforeInsert(): void {
+    this.id = generateEntityId(this.id, "iitem")
+  }
+}