Define an IP-configuration (static ip) for private endpoints

[fschirinzi]

Is your feature request related to a problem? Please describe.
Currently, it is not possible to define a static IP-address for private endpoints by defining the ip_configuration block, which is supported in the Private-Endpoint Terraform Resource >3.21.0

Describe the solution you'd like
By defining the ip_configuration block, I can set a static IP for a private endpoint.

Describe alternatives you've considered
The ip_configuration block is optional. Thus, no breaking change is introduced.

Additional context
The feature to set the ip_configuration is not supported yet in the terraform azurerm caf modules.
I created an Issue aztfmod/terraform-azurerm-caf#1689 and PR aztfmod/terraform-azurerm-caf#1691

I will also create a PR for this repository.