Task: Improve BDD tests

[MVrachev]

What is the task about?

There are multiple suggestions on how to improve the BDD tests.
Here is a list of them and for each of them we should either fix it or decide why not go forward with it.

• Add BDD tests for Token Feature to RSTUF API #369 (comment)
• Add BDD tests for Token Feature to RSTUF API #369 (comment)
• https://github.com/repository-service-tuf/repository-service-tuf-api/pull/369/files#r1242125446 : make explicit which feature is using my renaming token to access_token
• Add BDD tests for Token Feature to RSTUF API #369 (comment) - Add an invalid expire in payload scenario for the login
• Add BDD tests for Token Feature to RSTUF API #369 (comment) - can we reuse it?

Code of Conduct

• I agree to follow this project's Code of Conduct