User sign up

[Azmah-Bad]

Problem: there is currently no way to sign up new users in the backend.

Keep in mind that to create a new user, the API needs a the user to be already registered in Keycloak and have it's Keycloak-ID.

Solution:
create a new endpoint /signup in the API that takes new users info and creates a new user in Keycloak then link it with a user model in the backend afterwards.

Alternative solution:
Make the front end create both user in Keycloak and the API, this is a bit shaky.

[Debrej]

Problem is that the API must not have access to user password, the alternative solution is better as the front end waits for the answer from authentication server and once the user has been created in Keycloak it can create a user