refactor: replaced Batch Student child table with LMS Batch Enrollment doctype

lms/patches/v2_0/migrate_batch_student_data.py

@@ -0,0 +1,17 @@
+import frappe
+
+def execute():
+    students = frappe.get_all("Batch Student", fields=["student", "student_name", "username", "payment", "source", "parent", "confirmation_email_sent"])
+
+    for student in students:
+        doc = frappe.new_doc("LMS Batch Enrollment")
+        doc.member = student.student
+        doc.member_name = student.student_name
+        doc.member_username = student.username
+        doc.payment = student.payment
+        doc.source = student.source
+        doc.batch = student.parent
+        doc.confirmation_email_sent = student.confirmation_email_sent
+        doc.save()
+
+    frappe.delete_doc("DocType", "Batch Student")