Add tests for sorted() function

and check that sorted(list) produces same output as list.sort()

tests/basics/list_sort.py

 l = [1, 3, 2, 5]
+
 print(l)
+print(sorted(l))
 l.sort()
 print(l)
+print(l == sorted(l))
+
+print(sorted(l, key=lambda x: -x))
 l.sort(key=lambda x: -x)
 print(l)
+print(l == sorted(l, key=lambda x: -x))
+
+print(sorted(l, key=lambda x: -x, reverse=True))
 l.sort(key=lambda x: -x, reverse=True)
 print(l)
+print(l == sorted(l, key=lambda x: -x, reverse=True))
+
+print(sorted(l, reverse=True))
 l.sort(reverse=True)
 print(l)
+print(l == sorted(l, reverse=True))
+
+print(sorted(l, reverse=False))
 l.sort(reverse=False)
 print(l)
+print(l == sorted(l, reverse=False))