fix: Missing commits from hotfix branch (#17997)

* fix: merge conflict

* fix: restored missing set_gst_state_and_state_number function

* fix: style linting as per codacy

* fix: Fixes related to customer/lead merging

* fix: merge conflict

* fix: Fixes related to customer/lead merging

* fix: Assign isue/opportunity to user

* fix: Assign isue/opportunity to user

* fix: Replaced Invoice type by GST Category

* fix: merge conflict

* fix: merge conflict

* fix: test cases

* fix: test cases

requirements.txt

@@ -6,4 +6,5 @@ python-stdnum
 braintree
 gocardless_pro
 woocommerce
-pandas
+pandas
+plaid-python