Add unit tests for some surgeries, adds more APIs for unit tests to call (#52093)

* Add unit tests for medical related stuff

* Remove inaccurate assertion

code/modules/unit_tests/_unit_tests.dm

@@ -2,6 +2,14 @@
 //Keep this sorted alphabetically
 
 #ifdef UNIT_TESTS
+/// Asserts that a condition is true
+/// If the condition is not true, fails the test
+#define TEST_ASSERT(assertion, reason) if (!(assertion)) { return Fail("Assertion failed: [reason || "No reason"]") }
+
+/// Asserts that the two parameters passed are equal, fails otherwise
+/// Optionally allows an additional message in the case of a failure
+#define TEST_ASSERT_EQUAL(a, b, message) if ((a) != (b)) { return Fail("Expected [a] to be equal to [b].[message ? " [message]" : ""]") }
+
 #include "anchored_mobs.dm"
 #include "bespoke_id.dm"
 #include "card_mismatch.dm"
@@ -13,6 +21,10 @@
 #include "spawn_humans.dm"
 #include "species_whitelists.dm"
 #include "subsystem_init.dm"
+#include "surgeries.dm"
 #include "timer_sanity.dm"
 #include "unit_test.dm"
+
+#undef TEST_ASSERT
+#undef TEST_ASSERT_EQUAL
 #endif