feat(regional): Auto state wise taxation for GST India (#19469)

* feat(regional): Auto state wise taxation for GST India

* fix: Update gst category on addition of GSTIN

* fix: Codacy and travis fixes

* fix: Travis

* fix(test): Update GST category only if GSTIN field available

* fix: Test Cases

* fix: Do not skip accounts if place of supply is not present

* fix: Auto GST taxation for SEZ Party types

* fix: Automatic taxation for multi state

* fix: Codacy and travis fixes

* fix: Auto GST template selection in Sales Order

* fix: Move inter state check and source state to tax category

* fix: Remove unique check from tax template

* fix: Remove unique check from tax template

* fix: Address fetching logic in Sales

* fix: fecth tax template on company address change

* fix: fetch company gstin on address change

* fix: company_gstin set value fix

* fix: Mutiple fixes and code refactor

* fix: Add missing semicolon

* fix: Company address fetching in sales invoice

* fix: Remove print statement

* fix: Import functools

* fix: Naming fixes and code cleanup

* fix: Iteritems compatibility for python 3

erpnext/patches/v12_0/add_export_type_field_in_party_master.py

@@ -0,0 +1,40 @@
+from __future__ import unicode_literals
+import frappe
+from erpnext.regional.india.setup import make_custom_fields
+
+def execute():
+
+	company = frappe.get_all('Company', filters = {'country': 'India'})
+	if not company:
+		return
+
+	make_custom_fields()
+
+	frappe.reload_doctype('Tax Category')
+	frappe.reload_doctype('Sales Taxes and Charges Template')
+	frappe.reload_doctype('Purchase Taxes and Charges Template')
+
+	# Create tax category with inter state field checked
+	tax_category =  frappe.db.get_value('Tax Category', {'name': 'OUT OF STATE'}, 'name')
+
+	if not tax_category:
+		inter_state_category = frappe.get_doc({
+			'doctype': 'Tax Category',
+			'title': 'OUT OF STATE',
+			'is_inter_state': 1
+		}).insert()
+
+		tax_category = inter_state_category.name
+
+	for doctype in ('Sales Taxes and Charges Template', 'Purchase Taxes and Charges Template'):
+		template = frappe.db.get_value(doctype, {'is_inter_state': 1, 'disabled': 0}, ['name'])
+		if template:
+			frappe.db.set_value(doctype, template, 'tax_category', tax_category)
+
+		frappe.db.sql("""
+			DELETE FROM `tabCustom Field`
+			WHERE fieldname = 'is_inter_state'
+			AND dt IN ('Sales Taxes and Charges Template', 'Purchase Taxes and Charges Template')
+		""")
+
+