Defaults in Item Group (#14874)

* Add Defaults table in Item Group

* Fetch defaults from Item group if not found in Item

* Add patch

* Remove default fields from Item Group

* Set query for defaults

* Fix Codacy

* Modify test records

* Modify budget.py and sales_order.py

* Remove join from query

* Else condition to avoid error if no defaults found

* refrain from making item test records before item_group

* default cost center fetch correction

* Remove tab item group from query

erpnext/controllers/buying_controller.py

@@ -79,6 +79,12 @@ class BuyingController(StockController):
 					{"parent": d.item_code, "company": self.company}, "default_supplier")
 				if supplier:
 					self.supplier = supplier
+				else:
+					item_group = frappe.db.get_value("Item", d.item_code, "item_group")
+					supplier = frappe.db.get_value("Item Default",
+					{"parent": item_group, "company": self.company}, "default_supplier")
+					if supplier:
+						self.supplier = supplier
 					break
 
 	def validate_stock_or_nonstock_items(self):