This is an enhancement to MDL-35063 "Add setting for cron action after enrolment expiration - enrol_manual".
There was some discussion of it there. This adds an option to suspend the ser without deleting their roles
and other information.

With the recently merged MDL-35063, you can either have an expiration event AND delete data (roles and role dependent data),
or not have an expiration event and not delete anything. This patch adds the option to fire an event but NOT remove roles.
Like MDL-35063, this patch marks the enrolment "suspended", partially as a flag to avoid firing the event repeatedly.

To reproduce:
In Site administration ⟩ Plugins ⟩ Enrollments ⟩ Manual enrollments, set Enrolment expiration action to
"Disable course enrolment and remove roles".
Let an enrolment expire and the cron run.

What happens:
The enrolment is suspended, and the user data is removed. For example, with the "student" role removed, their grades are no longer available.

What is desired:
With this patch, one can avoid deleting student data by using the new ""Disable course enrolment" option
rather than the existing ""Disable course enrolment and remove roles" option.