[MIRROR] Adds Modular Ruins [MDB IGNORE] (#10760)

* Adds Modular Ruins (#64077)

Adds a new system to allow mappers to randomly load modular map segments.

For implementation details and a tutorial check the included README.md.

* Adds Modular Ruins

Co-authored-by: Thunder12345 <Thunder12345@users.noreply.github.com>

code/modules/unit_tests/_unit_tests.dm

@@ -80,6 +80,7 @@
 #include "metabolizing.dm"
 #include "mob_spawn.dm"
 #include "modsuit.dm"
+#include "modular_map_loader.dm"
 #include "ntnetwork_tests.dm"
 #include "outfit_sanity.dm"
 #include "objectives.dm"

code/modules/unit_tests/modular_map_loader.dm

@@ -0,0 +1,10 @@
+/datum/unit_test/modular_map_loader
+
+/datum/unit_test/modular_map_loader/Run()
+	for (var/obj/modular_map_root/map_root_type as anything in subtypesof(/obj/modular_map_root))
+		var/config_file = initial(map_root_type.config_file)
+		if (!fexists(config_file))
+			Fail("[map_root_type] points to a config file which does not exist!")
+			continue
+		if (rustg_read_toml_file(config_file) == null)
+			Fail("[map_root_type] points to a config file which is invalid!")