Add core:container/rbtree

Add a red-black tree with configurable $Key and $Value.
Also includes tests that verify it maintains RB invariants, doesn't leak.

Originally based on the CC0 implementation from literateprograms.org.
But reworked to the same API used by @Yawning's excellent `core:container/avl` for ease of use.

tests/core/build.bat

@@ -3,30 +3,15 @@ set COMMON=-no-bounds-check -vet -strict-style
 set COLLECTION=-collection:tests=..
 set PATH_TO_ODIN==..\..\odin
 python3 download_assets.py
-echo ---
-echo Running core:image tests
-echo ---
-%PATH_TO_ODIN% run image    %COMMON% -out:test_core_image.exe || exit /b
-
 echo ---
 echo Running core:compress tests
 echo ---
 %PATH_TO_ODIN% run compress %COMMON% -out:test_core_compress.exe || exit /b
 
 echo ---
-echo Running core:strings tests
+echo Running core:container tests
 echo ---
-%PATH_TO_ODIN% run strings %COMMON% -out:test_core_strings.exe || exit /b
-
-echo ---
-echo Running core:hash tests
-echo ---
-%PATH_TO_ODIN% run hash %COMMON% -o:size -out:test_core_hash.exe || exit /b
-
-echo ---
-echo Running core:odin tests
-echo ---
-%PATH_TO_ODIN% run odin %COMMON% -o:size -out:test_core_odin.exe || exit /b
+%PATH_TO_ODIN% run container %COMMON% %COLLECTION% -out:test_core_container.exe || exit /b
 
 echo ---
 echo Running core:crypto tests
@@ -45,9 +30,19 @@ rem %PATH_TO_ODIN% run encoding/hxa    %COMMON% %COLLECTION% -out:test_hxa.exe |
 %PATH_TO_ODIN% run encoding/base64 %COMMON% -out:test_base64.exe || exit /b
 
 echo ---
-echo Running core:math/noise tests
+echo Running core:fmt tests
 echo ---
-%PATH_TO_ODIN% run math/noise %COMMON% -out:test_noise.exe || exit /b
+%PATH_TO_ODIN% run fmt %COMMON% %COLLECTION% -out:test_core_fmt.exe || exit /b
+
+echo ---
+echo Running core:hash tests
+echo ---
+%PATH_TO_ODIN% run hash %COMMON% -o:size -out:test_core_hash.exe || exit /b
+
+echo ---
+echo Running core:image tests
+echo ---
+%PATH_TO_ODIN% run image    %COMMON% -out:test_core_image.exe || exit /b
 
 echo ---
 echo Running core:math tests
@@ -59,6 +54,21 @@ echo Running core:math/linalg/glsl tests
 echo ---
 %PATH_TO_ODIN% run math/linalg/glsl %COMMON% %COLLECTION% -out:test_linalg_glsl.exe || exit /b
 
+echo ---
+echo Running core:math/noise tests
+echo ---
+%PATH_TO_ODIN% run math/noise %COMMON% -out:test_noise.exe || exit /b
+
+echo ---
+echo Running core:net
+echo ---
+%PATH_TO_ODIN% run net %COMMON% -out:test_core_net.exe || exit /b
+
+echo ---
+echo Running core:odin tests
+echo ---
+%PATH_TO_ODIN% run odin %COMMON% -o:size -out:test_core_odin.exe || exit /b
+
 echo ---
 echo Running core:path/filepath tests
 echo ---
@@ -69,47 +79,32 @@ echo Running core:reflect tests
 echo ---
 %PATH_TO_ODIN% run reflect %COMMON% %COLLECTION% -out:test_core_reflect.exe || exit /b
 
+echo ---
+echo Running core:runtime tests
+echo ---
+%PATH_TO_ODIN% run runtime %COMMON% %COLLECTION% -out:test_core_runtime.exe || exit /b
+
 echo ---
 echo Running core:slice tests
 echo ---
 %PATH_TO_ODIN% run slice %COMMON% -out:test_core_slice.exe || exit /b
 
+echo ---
+echo Running core:strings tests
+echo ---
+%PATH_TO_ODIN% run strings %COMMON% -out:test_core_strings.exe || exit /b
+
 echo ---
 echo Running core:text/i18n tests
 echo ---
 %PATH_TO_ODIN% run text\i18n %COMMON% -out:test_core_i18n.exe || exit /b
 
-echo ---
-echo Running core:net
-echo ---
-%PATH_TO_ODIN% run net %COMMON% -out:test_core_net.exe || exit /b
-
-echo ---
-echo Running core:slice tests
-echo ---
-%PATH_TO_ODIN% run slice %COMMON% -out:test_core_slice.exe || exit /b
-
-echo ---
-echo Running core:container tests
-echo ---
-%PATH_TO_ODIN% run container %COMMON% %COLLECTION% -out:test_core_container.exe || exit /b
-
 echo ---
 echo Running core:thread tests
 echo ---
 %PATH_TO_ODIN% run thread %COMMON% %COLLECTION% -out:test_core_thread.exe || exit /b
 
-echo ---
-echo Running core:runtime tests
-echo ---
-%PATH_TO_ODIN% run runtime %COMMON% %COLLECTION% -out:test_core_runtime.exe || exit /b
-
 echo ---
 echo Running core:time tests
 echo ---
-%PATH_TO_ODIN% run time %COMMON% %COLLECTION% -out:test_core_time.exe || exit /b
-
-echo ---
-echo Running core:fmt tests
-echo ---
-%PATH_TO_ODIN% run fmt %COMMON% %COLLECTION% -out:test_core_fmt.exe || exit /b
+%PATH_TO_ODIN% run time %COMMON% %COLLECTION% -out:test_core_time.exe || exit /b