TODO

2.0

Extensible vl::filesystem.
- Virtual or filter files/folders (even on root, for wasm or unit test).
- vl::filesystem::OSFileSystem static class to access file system as Filepath, File and Folder.
- vl::filesystem::InjectFileSystemImpl(vl::filesystem::IFileSystemImpl*), nullptr to cancel, a default implementation using vl::filesystem::OSFileSystem will take place.
- Need to affect FileStream.