CAS Fire Mission ghost notification (#4328)

# About the pull request

This PR adds a ghost notification for CAS Fire Missions.

# Explain why it's good for the game

Observer QoL

# 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: Morrow
add: Added CAS Fire Mission ghost notification
/:cl:

code/game/cas_manager/datums/cas_fire_envelope.dm

@@ -125,10 +125,6 @@
 		mission_error = mission.error_message(check_result)
 		return 0
 
-	if(target_turf && target_turf.signal_loc)
-		var/turf/TT = get_turf(target_turf.signal_loc)
-		if(TT && TT.z)
-			msg_admin_niche("[key_name(usr)] launching Fire Mission '[mission.name]' onto [target_turf.name] at ([TT.x],[TT.y],[TT.z]) [ADMIN_JMP(TT)]")
 	//actual firemission code
 	execute_firemission_unsafe(target_turf, offset, dir, mission)
 	return 1

code/game/cas_manager/datums/cas_fire_mission.dm

@@ -98,6 +98,17 @@
 	if(initial_turf == null || check(linked_console) != FIRE_MISSION_ALL_GOOD)
 		return FIRE_MISSION_NOT_EXECUTABLE
 
+	var/obj/effect/firemission_effect = new(initial_turf)
+
+	firemission_effect.icon = 'icons/obj/items/weapons/projectiles.dmi'
+	firemission_effect.icon_state = "laser_target2"
+	firemission_effect.mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	firemission_effect.invisibility = INVISIBILITY_MAXIMUM
+	QDEL_IN(firemission_effect, 5 SECONDS)
+
+	notify_ghosts(header = "CAS Fire Mission", message = "[usr ? usr : "Someone"] is launching Fire Mission '[name]' at [get_area(initial_turf)].", source = firemission_effect)
+	msg_admin_niche("[usr ? key_name(usr) : "Someone"] is launching Fire Mission '[name]' at ([initial_turf.x],[initial_turf.y],[initial_turf.z]) [ADMIN_JMP(initial_turf)]")
+
 	var/relative_dir
 	for(var/mob/M in range(15, initial_turf))
 		if(get_turf(M) == initial_turf)