Bill now displays Net, Tax, Discount and Gross Amounts

Stylings: The bill table rows are properly centred instead of aligned to top

bookie/src/app/sales/bills/bills.component.ts

@@ -62,4 +62,20 @@ export class BillsComponent implements OnInit {
   modifier(item: any): void {
     this.bs.modifier(item);
   }
+
+  netAmount(): number {
+    return this.bs.netAmount();
+  }
+
+  discountAmount(): number {
+    return this.bs.discountAmount();
+  }
+
+  taxAmount(): number {
+    return this.bs.taxAmount();
+  }
+
+  amount(): number {
+    return this.bs.amount();
+  }
 }