DEL /enrollments - 'Enrollment/s Not Found' is missing

[AleksandrMolchagin]

Description:

The DEL /enrollments method currently returns Enrollment/s deleted successfully even when no records are found.

Expected Behavior:

When no records are found, the API should return a 404 status code with the following response body:

404: 
  body:
    application/json:
      example:
        message: Enrollment/s Not Found    

When some enrollments are found and deleted while others are not found, the API should return a 206 status code with the following response body:

{
  "message": "Partial Success",
  "deleted": ["enrollment_id_1", "enrollment_id_2"],
  "not_found": ["enrollment_id_3", "enrollment_id_4"]
}