fix: Linter and minor code refactor

- Create an indexed map of stale packed items table to avoid loops to check if packed item row exists
- Reset packed items if row deletion takes place
- Renamed functions to self-explain them
- Split long function
- Reduce function calls inside function (makes it harder to follow through)

(cherry picked from commit 4c677eafe9)

erpnext/public/js/controllers/buying.js

@@ -441,7 +441,7 @@ erpnext.buying.get_items_from_product_bundle = function(frm) {
 				type: "GET",
 				method: "erpnext.stock.doctype.packed_item.packed_item.get_items_from_product_bundle",
 				args: {
-					args: {
+					row: {
 						item_code: args.product_bundle,
 						quantity: args.quantity,
 						parenttype: frm.doc.doctype,