fix: Async key provider and errors should be resolved internally -- dynamic JWTs in tests

[jmjf]

Generates JWTs dynamically in tests as requested by @mcollina on #335.

If there's a way to apply this change to the original PR, please point me toward it and I'll do it.

This PR includes the changes @NikitaFedorov1 made for PR 335. My understanding of his comment in 335 is that he does not intend to apply the test changes requested. I just changed a few lines in his tests (commit #5) so others can get the benefit of this fix.

I broke the tests several times before getting them right, so I know they can fail. 😄 Also confirmed response bodies/error details matched those from the hard coded tokens while working on the tests.

PR 335 description

False positive tests: test: Async key provider errors should be resolved internally

Fix & test fix: feat: Async key provider

Related issue: #334

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[NikitaIT]

Yes, I've been very busy lately and I completely forgot about it. It looks good. Thank you. Just hold this pr instead of mine.

[mcollina]

lgtm