Feature: Added product Stock Keeping Units to prevent duplicate products. A lot of refactoring because of this.

Removed: Reset Stock as it was never used and don't think it is even needed with this new batch system.
Fix: Incentive update was not working

overlord/src/app/rate-contract/rate-contract-detail/rate-contract-detail.component.ts

@@ -119,9 +119,7 @@ export class RateContractDetailComponent implements OnInit, AfterViewInit {
     if (this.product === null || price <= 0) {
       return;
     }
-    const oldFiltered = this.item.items.filter(
-      (x) => x.product.id === (this.product as Product).id,
-    );
+    const oldFiltered = this.item.items.filter((x) => x.sku.id === (this.product as Product).id);
     if (oldFiltered.length) {
       this.toaster.show('Danger', 'Product already added');
       return;
@@ -129,7 +127,7 @@ export class RateContractDetailComponent implements OnInit, AfterViewInit {
     this.item.items.push(
       new RateContractItem({
         price,
-        product: this.product,
+        sku: this.product,
       }),
     );
     this.resetAddRow();