Student user and student patient

[fderyckel]

It would be better to leave the choice to the school to decide if they create user and / or patient.
So redo the code in student doctype (to match the employee)

Create 2 buttons,
one to create student user (and link the user id back to the student)
one to create the student patient (no link here, the link will be on the student patient)

What happens when a student leave the school or is graduated:
status goes from enrolled to graduated