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/hooks.py

@@ -246,10 +246,10 @@ doc_events = {
 		"on_trash": "erpnext.regional.check_deletion_permission"
 	},
 	'Address': {
-		'validate': ['erpnext.regional.india.utils.validate_gstin_for_india', 'erpnext.regional.italy.utils.set_state_code']
+		'validate': ['erpnext.regional.india.utils.validate_gstin_for_india', 'erpnext.regional.italy.utils.set_state_code', 'erpnext.regional.india.utils.update_gst_category']
 	},
-	('Sales Invoice', 'Purchase Invoice', 'Delivery Note'): {
-		'validate': 'erpnext.regional.india.utils.set_place_of_supply'
+	('Sales Invoice', 'Sales Order', 'Delivery Note', 'Purchase Invoice', 'Purchase Order', 'Purchase Receipt'): {
+		'validate': ['erpnext.regional.india.utils.set_place_of_supply']
 	},
 	"Contact": {
 		"on_trash": "erpnext.support.doctype.issue.issue.update_issue",