Adapt the 'Certificates' field and modal

The 'Certificates' field needs to be implemented
to manage the different certificates associated
to a given user.

This solution adresses the following:
- Syncronization with the Metadata values
and parameters.
- Addition of a new certificate
- Deletion of an existing certificate
- Notification of the aforementioned
operations via toast notification

Signed-off-by: Carla Martinez <[email protected]>