feat(userspace/apps/test/libc_test): rewrite a lot of the code and improve debugging with vscode using .devcontainer

Signed-off-by: EnderIce2 <enderice2@protonmail.com>

Userspace/apps/test/libc_test/.editorconfig

@@ -0,0 +1,19 @@
+# EditorConfig is awesome: https://editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = tab
+indent_size = 4
+
+[Makefile]
+indent_style = tab
+
+[*.json]
+insert_final_newline = false
+
+[compose.yaml]
+indent_style = space