Enrollments (santa/osquery) can't be edited/removed once created

[arubdesu]

On the osquery/ and santa/configurations/ URL's under Enrollment, you cannot remove/edit enrollments once created

[np5]

The enrolled machines are linked to the enrollments, and this is how we then find the corresponding configuration for the different agents.

Some things we could do:

• Allow removal of enrollments without enrolled machines.
• Allow removal of enrollments with the corresponding enrolled machines (with extra confirmation). The corresponding agents will not be able to communicate with Zentral anymore.
• Add an attribute on the enrollments to expire them. Agents on the already enrolled machines will still be able to communicate with Zentral, but no new machines will be able to enroll.