Implement map tests for catching common errors. (#19204)

* Implement map tests for catching common errors.

- Adds test runner:
	- to make it easier to track things across test types
	- for example to ensure a fully specified log can be emitted

- Adds map tile test type:
	- when writing a test, coders implement CheckTile, which is
	  handed a single turf
	- when the test runner runs these tests, it iterates over
	  all turfs in the specified z-level, and runs each test's
	  CheckTile on each turf in turn.

- Adds two sample map tile tests:
	- check to see if a pipe exists on the same tile as a scrubber
	  or vent
	- check to see if a tile contains two cables, each with a center
	  node

* Review #1:

- Replace nested loops over map tiles with `block`
- Remove check for valid turf in individual tests, I think it's safe to
  assume `block` will always return legit turfs
- Added proper duration tracking for old tests
- Gave log file an appropriate extension
- Actually use `Fail` for tests

* whoops

* add more tests suggested by @Vi3trice

* Add some more tests courtesy @Bm0n and @Vi3trice

* windows are okay in space as long as it's nearspace

* Add failure threshold to prevent excessive logging.

Once this threshold is reached, a test will stop being processed for
every tile.

Note that this applies to `log_world` and `text2file` equally when
logging large amounts of failures.

* Document each test.

* Remove unnecessary reboot

* Let all map tests run to completion in CI matrix.

* I know what alphabetical means

code/controllers/subsystem/ticker.dm

@@ -329,7 +329,9 @@ SUBSYSTEM_DEF(ticker)
 	SSnightshift.check_nightshift(TRUE)
 
 	#ifdef UNIT_TESTS
-	RunUnitTests()
+	// Run map tests first in case unit tests futz with map state
+	GLOB.test_runner.RunMap()
+	GLOB.test_runner.Run()
 	#endif
 
 	// Do this 10 second after roundstart because of roundstart lag, and make it more visible