Print assertion message in the case of assertion failure

Description

The intended assertion message should print instead of a long exception, in the case that it's the assert function that fails.

[x] The code change is covered by unit tests. I have added tests that prove my fix is effective or that my feature works
[x] I have performed end-to-end test locally.
[x] New and existing unit tests pass locally with my changes
[x] I have commented my code, particularly in hard-to-understand areas
[x] I have made corresponding changes to the documentation
[x] My changes generate no new warnings
[x] I used clear names for everything
[x] I have performed a self-review of my own code

Package	Line Rate	Branch Rate	Complexity	Health
Microsoft.PowerApps.TestEngine	91%	87%	824	✔
Summary	91% (2168 / 2386)	87% (500 / 572)	824	✔