Bun Test matchers even/odd. Also, .toContains fix and truthy

[will-richards-ii]

Adds odd/even matchers.

• failing tests with boilerplate
• passing tests implementation
  Fixes .toContain in the case of an empty string.
  A few extra truthy test cases.

[Jarred-Sumner]

Did you run make codegen? There should be changes to a couple generated files due to this. Otherwise, these functions would never be called.

[will-richards-ii]

My bad. I did on my local, but did not think to include them in the commit. I should have looked at existing commits more closely. Also ran the ts and zig fmt commands.

[Jarred-Sumner]

Thank you