Add basic functional "smoke test"

[adhilto]

💡 Summary

Add a functional, end-to-end test that performs very basic validation of ScubaGoggles functionality.

Motivation and context

Currently all functional testing needs to be done manually, leading to delayed discovery of potential issues. Due to GWS's limited API, we can't implement full functional testing, but we could implement a basic "smoke test" which would allow us to quickly identify some issues.

Implementation notes

Dependent on:

• Add support for auth by service account #165
• Enhance Error handling #163

After those two PRs are merged, we can add a GitHub trigger that runs ScubaGoggles and performs basic validation of the report, such as:

• The provider output is valid json
• There is no missing output
• No API calls or functions produced exceptions

I recommend referring to the ScubaGear smoke test as a starting point for implementing this functionality.

See:

• https://github.com/cisagov/ScubaGear/blob/main/.github/workflows/run_smoke_test.yaml
• https://github.com/cisagov/ScubaGear/tree/main/Testing/Functional/SmokeTest

Acceptance criteria

• A basic smoke test has been implemented
• The smoke test has been added to the GitHub workflow

[LaurenBassett]

Just waiting on error handling PR #163

[adhilto]

Both dependent PRs have been merged into main, this issue is ready for development.