OPNSense package

[mlsmaycon]

Since we have the NetBird client being deployed in FreeBSD ports, we should be able to leverage it to run our client within OPNSense as a package and to manage it using the GUI.

The initial idea is to have a simple support, with a limited number of flags, status, and configuration. Below is a description of the tabs we need:

An authentication tab with Management URL and Setup Key input boxes and a Disconnect/Connect button. See PFSense example:

A Settings tab where the client can be configured. See PFSense example:

A Status tab with connection and peer, status, and package version information:

The status information can be copied as it will be displayed as text.

Relates to #2200 #415