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/mapload_space_verification.dm

@@ -1,6 +1,7 @@
 /// Verifies that there are no space turfs inside a station area, or on any planetary z-level. Sometimes, these are introduced during the load of the map and are not present in the DMM itself.
 /// Let's just make sure that we have a stop-gap measure in place to catch these if they pop up so we don't put it onto production servers should something errant come up.
 /datum/unit_test/maptest_mapload_space_verification
+	test_flags = UNIT_TEST_MAP_TEST
 	// This test is quite taxing time-wise, so let's run it later than other faster tests.
 	priority = TEST_LONGER