test: add tests for AssemblyScript SDK Transform

[JairusSW]

Implement tests for AssemblyScript SDK transform

I implemented a basic test suite using node's builtin testing library which provided basic testing for the ASC Transform.

Checklist

• Code compiles correctly and linting passes locally
• For all code changes, an entry added to the CHANGELOG.md file describing and linking to this PR
• Tests added for new functionality, or regression tests for bug fixes added as applicable

[mattjohnsonpint]

Can you please write these in typescript? Thanks.

[JairusSW]

@mattjohnsonpint yeah, I can do that
Just have to tweak the tsconfig a bit

[JairusSW]

@mattjohnsonpint I didn't end up compiling the tests to js with tsc, instead I added node's new --experimental-strip-types flag so it can execute the TypeScript files directly
Its experimental, so if you want, I can always switch it back to tsc, just lmk

[mattjohnsonpint]

For tests, the flag is fine as long as it works. We can always replace it with tsc later if fails on anything.

Please add our standard copyright header to the newly added .ts files, and then I'll approve. Thanks.