Better Unit Tests - Runs All Of Them On A Single Map (exc. map unit tests) and C&D Split-Up (#96368)

## About The Pull Request

### Don't run every single test

I've had this on my mind for several months and it being brought up
recently reminded me so here we are.

Unit tests only run on `runtimestation_minimal.dmm` now with the
exception of map tests. The following unit tests are declared as map
tests but I didn't see any map dependent logic so 🤷
- `/datum/unit_test/maptest_baseturfs_unmodified_scrape`
- `/datum/unit_test/maptest_baseturfs_placed_on_top`
- `/datum/unit_test/maptest_baseturfs_placed_on_bottom`
- `/datum/unit_test/maptest_get_turf_pixel`
- `/datum/unit_test/maptest_load_map_security`
- `/datum/unit_test/maptest_modular_map_loader`
- `/datum/unit_test/maptest_turf_icons`

`/datum/unit_test/subsystem_init` isn't really a mapping unit test but I
figured somehow, someway, maps might fuck with subsystem initializations
so I just decided to include it.

### Splits up the create & destroy test

Idk, pretty simple. Create & destroy is now split up across all
integration tests and ran in parallel.

## Why It's Good For The Game

oranges promised me "500 nzd" yo

## Changelog

No player facing changes

code/modules/unit_tests/_unit_tests.dm

@@ -39,7 +39,7 @@
 /// *Only* run the test provided within the parentheses
 /// This is useful for debugging when you want to reduce noise, but should never be pushed
 /// Intended to be used in the manner of `TEST_FOCUS(/datum/unit_test/math)`
-#define TEST_FOCUS(test_path) ##test_path { focus = TRUE; }
+#define TEST_FOCUS(test_path) ##test_path { test_flags = UNIT_TEST_FOCUS; }
 
 /// Run the test provided within the parentheses run_count times
 /// Useful for debugging flaky tests that only fail sometimes
@@ -67,6 +67,16 @@
  */
 #define TEST_AFTER_CREATE_AND_DESTROY INFINITY
 
+// Unit test bitflags
+
+/// If any unit test has this bitflag, only unit tests with UNIT_TEST_FOCUS will run.
+#define UNIT_TEST_FOCUS (1<<0)
+/// This unit test only runs on specially designated unit test maps (Should only ever be one).
+#define UNIT_TEST_DEBUG_MAP_ONLY (1<<1)
+
+#define UNIT_TEST_BASIC (UNIT_TEST_DEBUG_MAP_ONLY)
+#define UNIT_TEST_MAP_TEST (NONE)
+
 /// Change color to red on ANSI terminal output, if enabled with -DANSICOLORS.
 #ifdef ANSICOLORS
 #define TEST_OUTPUT_RED(text) "\x1B\x5B1;31m[text]\x1B\x5B0m"