[POS] Show stock quantity of items

- frappe/erpnext#8247

erpnext/accounts/page/pos/pos.js

@@ -951,6 +951,7 @@ erpnext.pos.PointOfSale = erpnext.taxes_and_totals.extend({
 						item_price: format_currency(me.price_list_data[obj.name], me.frm.doc.currency),
 						item_name: obj.name === obj.item_name ? "" : obj.item_name,
 						item_image: obj.image,
+						item_stock: __('Stock') + ": " + me.get_actual_qty(obj),
 						color: frappe.get_palette(obj.item_name),
 						abbr: frappe.get_abbr(obj.item_name)
 					})).tooltip().appendTo($wrap);

erpnext/public/js/pos/pos_item.html

@@ -1,7 +1,7 @@
 <div class="pos-item-wrapper image-view-item" data-item-code="{{item_code}}">
 	<div class="image-view-header doclist-row">
 		<div class="list-value">
-			<a class="grey list-id" data-name="{{item_code}}" title="{{ item_name || item_code}}">{{item_name || item_code}}</a>
+			<a class="grey list-id" data-name="{{item_code}}" title="{{ item_name || item_code}}">{{item_name || item_code}}<br>({{item_stock}})</a>
 		</div>
 	</div>
 	<div class="image-view-body">