If casting a string fails then raise a TypeError. This is potentially an API
breaking change; chosen as the lesser evil vs. allowing silent errors.
`cast()` relies on `bytes(obj)` & `str(obj)` returning the respective
supertype. That's no longer the case for `AnsibleUnsafeBytes` &
`AnsibleUnsafeText`; since fixes/mitigations for CVE-2023-5764.
fixes#1046, refs #977
See also
- https://github.com/advisories/GHSA-7j69-qfc3-2fq9
- https://github.com/ansible/ansible/pull/82293
e.g. assert x == y -> self.assertEqual(x, y);
self.assertTrue(isinstance(x, y)) -> self.assertIsInstance(x, y)
These specific methods give more useful errors in the case of a test
failure.
Alex Willmer