Feature: DNAT Support (v26.1)

### Link to API

_No response_

### Description

The [OPNsense roadmap](https://opnsense.org/roadmap/) shows that DNAT will be migrated to MVC/API in Version 26.1:

* DNAT (port forward) API support [*](https://github.com/opnsense/core/issues/8401)