test: remove unit tests that are already covered by the e2e suite

[ctran88]

What's New?

• removes mock unit tests that are already covered in the e2e workflow
• removes example server

Screenshots (if appropriate):

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have manually tested my code thoroughly
• I have added/updated inline documentation for public facing interfaces if relevant
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing integration and unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Additional context

[ctran88]

i wasn't sure if there was an additional use for the example server or not. i can see it both ways, so if it's preferred that this stay in i will revert its removal

[ctran88]

i left the set_server_url method in because the default base path needs to be updated with the app id:

passage-flex-rust/src/openapi/apis/configuration.rs

Line 42 in 73bac7a

base_path: "https://api.passage.id/v1/apps/TODO".to_owned(),