Payment Tool Feature

@nabinhait @anandpdoshi @rmehta Payment Tool Feature, please review and suggest
This would be much more legible:

```
sales_order_customer = frappe.db.get_value("Sales Order", d.against_sales_order, "customer")
account_customer = frappe.db.get_value("Account", d.account, "master_name")
if sales_order_customer != account_customer:
```