Add feature label for a patient who have been exempted for payment

[Moricembiaji]

Is your feature request related to a problem? Please describe.
Currently, there is no label indicating that the patient who has been given an exemption

Describe the solution you'd like
Add a feature label for a patient who has been exempted from payment once granted exemption. The label should change status from cash to exemption and be added to the list of exempted patients.

Additional context