[NFC] Put back email test without tokens and enhance a little

[demeritcowboy]

Overview

Followup to #21386 to just have a test that checks the code doesn't assume there's always a token present.

This is the same test as the original Basic test but with some $mut mail checking added.

[civibot]

(Standard links)

• If this is your first pull-request for CiviCRM, please browse CONTRIBUTING.md for information about the development and testing processes.
• If you are reviewing this pull-request, you may wish to consult the test sites and the Review Standards (long template, short template).

[seamuslee001]

MOP