Accept a client_id in the body parameters of the enrollments/ticket endpoint

Feature: Accept a client_id in the body parameters of the POST /v2/guardian/enrollments/ticket endpoint.

Description: The email template used for enrollment tickets populates the application related variables only with the available tenant’s info since it doesn’t have any application related info, like the POST /v2/organizations/{id}/invitations endpoint has for example.

Use-case: I would like to remind the user on which application they were when initialing the enrollment and redirect them back to the same app once the setup complete.