Issue Description: 

Secret values will now be masked when retrieving processor data. Their value will be an empty object {}, as expected by the schema catalog for this kind of sensitive fields.

The UI has to display some asterisks instead of the empty object when in read only mode.

Inside the processor edit form, the secret input fields will display no value. A description below the field will explain the value is not displayed because it's sensitive and that a new one can be set. 

So for processor edit we need a double conversion:

• Empty object to empty string when setting up the form model
• Empty string to empty object when saving the form (only for sensitive fields and only if the user didn't provide a new value)

The backend will take care of ignoring the empty object value for sensitive fields when editing a processor, so to keep the original one.

Acceptance Criteria: Sensitive fields are masked when looking at processor details page. They are replaced with an empty value in the processor edit form.

Out of Scope: <Here you need to fill in what is out of scope for this issue and then create new issues if necessary in the backlog for the work>

Additional Information: <Add any additional information here that may be helpful to people reading the ticket>