chore: Drive E-commerce via Website Item

- Removed Shopping Cart Settings
- Portal fully driven via E Commerce Settings
- All Item listing querying will happen via ProductQuery engine only
- Product Listing via Website Items
- removed redundant code
- Moved all website logic from Item to Website Item

erpnext/setup/setup_wizard/operations/install_fixtures.py

@@ -492,7 +492,7 @@ def install_defaults(args=None):
 
 		# Shopping cart: needs price lists
 		{
-			"doctype": "Shopping Cart Settings",
+			"doctype": "E Commerce Settings",
 			"enabled": 1,
 			'company': args.company_name,
 			# uh oh