Allowing linking the service account to standalone projects (projects not linked to an organization)

The CMP does not support for now linking the service account standalone projects, that do not belong to an organisation.
It has to do with the fact that we create job sinks at the organisation level.

Idea:
1) allow the customer to select whether or not he has a standalone project or a project within an org
2) based on the previous answer, adapt where the job sinks are created