feat: inventory items api (#2971)

What:
Admin endpoints to handle inventory items and their stock levels per location

FIXES: CORE-975

Co-authored-by: Sebastian Rindom <7554214+srindom@users.noreply.github.com>

packages/medusa/src/interfaces/services/stock-location.ts

@@ -28,4 +28,6 @@ export interface IStockLocationService {
   create(input: CreateStockLocationInput): Promise<StockLocationDTO>
 
   update(id: string, input: UpdateStockLocationInput): Promise<StockLocationDTO>
+
+  delete(id: string): Promise<void>
 }