Code cleanup: Sorting (#83017)

## About The Pull Request
1. Removes code duplication 
2. Fully documents `sortTim()`
3. Makes a define with default sortTim behavior, straight and to the
point for 95% of cases
4. Migrates other sorts into the same file
5. Removes some redundancy where they're reassigning a variable using an
in place sorter

For the record, we only use timSort
## Why It's Good For The Game
More documentation, easier to read, uses `length` over `len`, etc
Should be no gameplay effect at all

code/modules/unit_tests/unit_test.dm

@@ -340,7 +340,7 @@ GLOBAL_VAR_INIT(focused_tests, focused_tests())
 	if(length(focused_tests))
 		tests_to_run = focused_tests
 
-	tests_to_run = sortTim(tests_to_run, GLOBAL_PROC_REF(cmp_unit_test_priority))
+	sortTim(tests_to_run, GLOBAL_PROC_REF(cmp_unit_test_priority))
 
 	var/list/test_results = list()