fix(pos): multiple pos fixes and additions (#24227)

* fix: make custom fields in pos invoice similar to sales invoice

* feat: allow/disallow rate & discount change

* fix: any pos profile can be selected while creating pos opening

* fix: cannot add item to cart

* fix: validate phone payment only if payment request exists

* fix: replace pos payment method patch

* chore: rearrange item & customer group filter

* fix: allow/disallow invoice level discount

* fix: updating qty of item with uom having space char

* fix: move configuration checbox to config section

* fix: invalid item rate trigger

* fix: cannot remove item from draft invoices

* fix: customer currency not set in pos invoice

* fix: duplicate item error message

* fix: sales uom not fetched in pos invoice

* fix: cannot add taxes to pos invoice for uae region

* fix: cannot merge pos invoice into credit note

* fix: tax calculation while merging pos invoices

* feat: delete draft orders from order list

* fix: merging of pos invoice with pricing rules

erpnext/patches/v13_0/create_uae_pos_invoice_fields.py

@@ -0,0 +1,14 @@
+# Copyright (c) 2019, Frappe and Contributors
+# License: GNU General Public License v3. See license.txt
+
+from __future__ import unicode_literals
+
+import frappe
+from erpnext.regional.united_arab_emirates.setup import make_custom_fields
+
+def execute():
+	company = frappe.get_all('Company', filters = {'country': ['in', ['Saudi Arabia', 'United Arab Emirates']]})
+	if not company:
+		return
+
+	make_custom_fields()