Fixes Camera Monitoring Console UI restricted network access (#21758)

Fixes https://github.com/Aurorastation/Aurora.3/issues/21757.

Changes made in https://github.com/Aurorastation/Aurora.3/pull/21734
allowed for camera monitoring consoles to launch their own headless
versions of the Camera Monitoring app, but the Horizon's mapped
consoles, unlike Runtime's, have some dedicated network restrictions.

This PR adds a var to the camera_monitor program that can hold the src
of the UI, which in the case of camera monitoring consoles, will
restrict the available networks displayed to those set on the console
obj itself.

changes:
- bugfix: "Dedicated camera monitoring console UIs now display only that
console's predefined networks, not all networks to which the user has
access (as is the case with regular use of the camera monitoring app.)"
- bugfix: "Removes an unnecessary process() func from camera monitoring
consoles."

code/modules/modular_computers/file_system/programs/security/camera.dm

@@ -44,6 +44,8 @@
 	tgui_id = "CameraMonitoring"
 	var/obj/machinery/camera/current_camera
 	var/current_network
+	/// Used for camera monitor consoles from which this interface can be launched. If it exists, only provide that console's "console_networks" networks.
+	var/list/monitored_networks = list()
 
 /datum/computer_file/program/camera_monitor/ui_data(mob/user)
 	var/list/data = initial_data()
@@ -52,7 +54,17 @@
 	data["current_network"] = current_network
 
 	var/list/all_networks = list()
-	for(var/network in SSatlas.current_map.station_networks)
+	var/list/available_networks = list()
+
+	// If this UI was generated from a camera monitoring console, then only that console's networks will be available...
+	if(monitored_networks && (length(monitored_networks) >= 1))
+		available_networks = monitored_networks
+
+	// ...otherwise (if it was launched from a standard modular computer), get all networks to which the user has access.
+	else
+		available_networks = SSatlas.current_map.station_networks
+
+	for(var/network in available_networks)
 		all_networks += list(
 			list(
 				"tag" = network,
@@ -205,7 +217,6 @@
 		return FALSE
 	return TRUE
 
-
 // ERT Variant of the program
 /datum/computer_file/program/camera_monitor/ert
 	filename = "ntcammon"