Sensor tower gets tacmap icon (#7444)

# About the pull request

sensor tower now gets tacmap icon displayed to everyone

# Explain why it's good for the game

makes it easier for both sides to find sensors and possibly allow for
randomized sensor location if someone wants to do that. Knowing where
sensors are is needless map knowladge check for both sides and they
should know the same they know comm locations


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
imageadd: tacmap icon for sensor tower (displayed to all factions)
/:cl:

---------

Co-authored-by: vincibrv <[email protected]>
Co-authored-by: Blundir <[email protected]>

code/modules/desert_dam/motion_sensor/sensortower.dm

@@ -26,6 +26,10 @@
 	/// weakrefs of xenos temporarily added to the marine minimap
 	var/list/minimap_added = list()
 
+/obj/structure/machinery/sensortower/Initialize(mapload, ...)
+	. = ..()
+	SSminimaps.add_marker(src, z, MINIMAP_FLAG_ALL, "sensor_tower")
+
 
 /obj/structure/machinery/sensortower/update_icon()
 	..()