[client] Refactor/iface pkg (#2646)

Refactor the flat code structure

client/iface/device/kernel_module_freebsd.go

@@ -0,0 +1,18 @@
+package device
+
+// WireGuardModuleIsLoaded check if kernel support wireguard
+func WireGuardModuleIsLoaded() bool {
+	// Despite the fact FreeBSD natively support Wireguard (https://github.com/WireGuard/wireguard-freebsd)
+	//  we are currently do not use it, since it is required to add wireguard kernel support to
+	//   - https://github.com/netbirdio/netbird/tree/main/sharedsock
+	//   - https://github.com/mdlayher/socket
+	// TODO: implement kernel space
+	return false
+}
+
+// ModuleTunIsLoaded check if tun module exist, if is not attempt to load it
+func ModuleTunIsLoaded() bool {
+	// Assume tun supported by freebsd kernel by default
+	// TODO: implement check for module loaded in kernel or build-it
+	return true
+}