test: cover thenables when we check for promises

Added tests that cover the issue when assert.rejects() and
assert.doesNotReject() should not accept Thenables without
a `catch` method or any Thenable function with `catch` and
`then` methods attached.

PR-URL: https://github.com/nodejs/node/pull/24219


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>