fix: typerror on tree doctypes - Item Group, Customer Group, Supplier Group and Territory (#38870) * refactor: typerror on set_root_readonly * refactor: remove 'cur_frm' usage in supplier_group * refactor: remove 'cur_frm' usage in territory.js * refactor: remove 'cur_frm' from sales_person.js (cherry picked from commit 6d5bdc6c68dfda915972f3747de752b8fad7cdb5) Co-authored-by: ruthra kumar <ruthra@erpnext.com>