REST API - Fake Authentication Provider

[valentinajemuovic]

Ticket #74 (REST API - Contract Testing) cannot be completed yet because of authentication.

There are limited options regarding Pact and authentication, possibilities such as modifying the request https://docs.pact.io/provider/handling_auth

However, from a logical perspective, to keep our integration test isolated, it means we would avoid the real auth.

Thus, we'd have the following:

• System Test: BankAccountControllSystemTest - this continues to use the real auth provider (using KeyCloak) since it's in the category of e2e testing
• Integration Test & Component tests would not reach out to anything external (i.e. no Keycloak) hence the Fake authentication provider would be used instea