Code cleanup for item price stock report and fix report was not exporting properly in excel (#12427)

diff --git a/erpnext/stock/report/item_price_stock/item_price_stock.py b/erpnext/stock/report/item_price_stock/item_price_stock.py
index 4cd8fdd..9ee7d05 100644
--- a/erpnext/stock/report/item_price_stock/item_price_stock.py
+++ b/erpnext/stock/report/item_price_stock/item_price_stock.py
@@ -12,13 +12,52 @@
 
 def get_columns():
 	return [
-		_("Item Name") + ":Link/Item:150",
-		_("Warehouse") + ":Link/Warehouse:130",
-		_("Stock Available") + ":Float:120",
-		_("Buying Price List") + ":Data:130",
-		_("Buying Rate") + ":Currency:110",
-		_("Selling Price List") + ":Data:130",
-		_("Selling Rate") + ":Currency:110"
+		{
+			"label": _("Item Name"),
+			"fieldname": "item_name",
+			"fieldtype": "Link",
+			"options": "Item",
+			"width": 120
+		},
+		{
+			"label": _("Warehouse"),
+			"fieldname": "warehouse",
+			"fieldtype": "Link",
+			"options": "Warehouse",
+			"width": 120
+		},
+		{
+			"label": _("Stock Available"),
+			"fieldname": "stock_available",
+			"fieldtype": "Float",
+			"width": 120
+		},
+		{
+			"label": _("Buying Price List"),
+			"fieldname": "buying_price_list",
+			"fieldtype": "Link",
+			"options": "Price List",
+			"width": 120
+		},
+		{
+			"label": _("Buying Rate"),
+			"fieldname": "buying_rate",
+			"fieldtype": "Currency",
+			"width": 120
+		},
+		{
+			"label": _("Selling Price List"),
+			"fieldname": "selling_price_list",
+			"fieldtype": "Link",
+			"options": "Price List",
+			"width": 120
+		},
+		{
+			"label": _("Selling Rate"),
+			"fieldname": "selling_rate",
+			"fieldtype": "Currency",
+			"width": 120
+		}
 	]
 
 def get_data(filters, columns):
@@ -32,8 +71,8 @@
 	if filters.get("item_code"):
 		conditions += "where a.item_code=%(item_code)s"
 
-	item_results = frappe.db.sql("""select a.item_code as name,a.name as price_list_name,
-		b.warehouse as warehouse,b.actual_qty as actual_qty
+	item_results = frappe.db.sql("""select a.item_code as item_name, a.name as price_list_name,
+		b.warehouse as warehouse, b.actual_qty as actual_qty
 		from `tabItem Price` a left join `tabBin` b
 		ON a.item_code = b.item_code
 		{conditions}"""
@@ -45,19 +84,30 @@
 	buying_price_map = get_buying_price_map(price_list_names)
 	selling_price_map = get_selling_price_map(price_list_names)
 
-	item_dicts = [{"Item Name": d['name'],"Item Price List": d['price_list_name'],"Warehouse": d['warehouse'],
-				"Stock Available": d['actual_qty']} for d in item_results]
-	for item_dict in item_dicts:
-		price_list = item_dict["Item Price List"]
-		item_dict["Warehouse"] = item_dict["Warehouse"] or ""
-		item_dict["Stock Available"] = item_dict["Stock Available"] or 0
-		if buying_price_map.get(price_list):
-			item_dict["Buying Price List"] = buying_price_map.get(price_list)["Buying Price List"] or ""
-			item_dict["Buying Rate"] = buying_price_map.get(price_list)["Buying Rate"] or 0
-		if selling_price_map.get(price_list):
-			item_dict["Selling Price List"] = selling_price_map.get(price_list)["Selling Price List"] or ""
-			item_dict["Selling Rate"] = selling_price_map.get(price_list)["Selling Rate"] or 0
-	return item_dicts
+	result = []
+	if item_results:
+		for item_dict in item_results:
+			data = {
+				'item_name': item_dict.item_name,
+				'warehouse': item_dict.warehouse,
+				'stock_available': item_dict.actual_qty or 0,
+				'buying_price_list': "",
+				'buying_rate': 0.0,
+				'selling_price_list': "",
+				'selling_rate': 0.0
+			}
+
+			price_list = item_dict["price_list_name"]
+			if buying_price_map.get(price_list):
+				data["buying_price_list"] = buying_price_map.get(price_list)["Buying Price List"] or ""
+				data["buying_rate"] = buying_price_map.get(price_list)["Buying Rate"] or 0
+			if selling_price_map.get(price_list):
+				data["selling_price_list"] = selling_price_map.get(price_list)["Selling Price List"] or ""
+				data["selling_rate"] = selling_price_map.get(price_list)["Selling Rate"] or 0
+
+			result.append(data)
+
+	return result
 
 def get_buying_price_map(price_list_names):
 	buying_price = frappe.db.sql("""