NethVoice CTI: privacy parameter management is missing

[andrea-marchionni]

NethVoice CTI includes a feature to obscure phone numbers that do not pertain to personal calls.
This feature is controlled by the parameter:

"privacy_numbers": "xxx"

Currently, the parameter replaces a fixed number of digits with "x" there is no option to specify the exact number of digits to mask.

To enhance flexibility, it is recommended to move this parameter to the environment configuration.
This approach will allow admins to adjust the number of hidden digits easily without risking the loss of the configuration after a container restart or update.