filesystem: use std for CreateFolder

Remove custom platform implementation of `CreateFolder` and replace uses
with `std::filesystem::create_directories` which creates paths
recursively.

src/xenia/base/filesystem.cc

@@ -18,7 +18,7 @@ bool CreateParentFolder(const std::filesystem::path& path) {
   if (path.has_parent_path()) {
     auto parent_path = path.parent_path();
     if (!std::filesystem::exists(parent_path)) {
-      return CreateFolder(parent_path);
+      return std::filesystem::create_directories(parent_path);
     }
   }
   return true;