Added delivery date in SO parent form. Fixes #10104 (#10155)

* Added delivery date in SO parent form. Fixes #10104

* UI tests for sales order delivery date
diff --git a/erpnext/tests/ui/tests.txt b/erpnext/tests/ui/tests.txt
index 42233dc..40b1c59 100644
--- a/erpnext/tests/ui/tests.txt
+++ b/erpnext/tests/ui/tests.txt
@@ -2,4 +2,5 @@
 erpnext/accounts/doctype/account/test_account.js
 erpnext/crm/doctype/lead/test_lead.js
 erpnext/crm/doctype/opportunity/test_opportunity.js
-erpnext/selling/doctype/quotation/test_quotation.js
\ No newline at end of file
+erpnext/selling/doctype/quotation/test_quotation.js
+erpnext/selling/doctype/sales_order/test_sales_order.js
\ No newline at end of file